The goal of presuppositional apologetics, or at least some versions of it as I understand them, is to prove the necessity of the Christian worldview: Christianity is true and only Christianity, and all others are incoherent and inconsistent and cannot account for reality. Christianity, also, is necessarily true, or so they say.

Now for a thing to be necessarily true is two things, though they both basically are the same: it must be true in every possible world, and its denial must entail a contradiction. There are problems with the claim that Christianity is necessarily true, one of them being the fact that no Christian presuppositionalist has shown that at least all the other worldviews we know about are inconsistent and contradictory, let alone all possible worldviews which are not Christianity. The difficulty of that sort of task aside, however, it can easily be shown that Christianity is not necessarily true:

Imagine a possible world where God creates man and never decrees that man sins (or, if you don't believe that God decrees sin, imagine a world where he creates men without free will and they always do good). In such a world, there is no incarnation and no atonement, because there is no need, because there is neither of these things, there is no Christianity. Christianity is not true in this worldview because there is no sin and no Jesus of Nazareth who took on the sins of the world. So Christianity is not necessarily true.

A presuppositionalist can defend his claim to the necessary truth of Christianity by supposing that such a world is not actually possible--though it's hard to see how that might be the case. It certainly seems to be free of contradiction and absurdity. (Unless the presuppositionalist wants to claim that, because of God's nature, he decrees that men sin necessarily--but that is a mighty strange claim and doesn't seem to be very plausible.)

What does the presuppositionalist argue for, then? For the necessary existence of the Christian God? Even if he can argue for that (even though it seems troublesome and difficult enough), that doesn't prove Christianity true at all. He can exist and Christianity still be false, as was shown above. Then the presuppositionalist is at best arguing for a form of theism and not Christianity, which was his purpose from the beginning.

What can the presuppositionalist do about all this? Perhaps he ought to adopt a more liberal approach, distancing himself from the fundamentalism of Cornelius Van Til and Greg Bahnsen, arguing merely that presupposing Christianity makes a great deal of sense about the universe, a sort of abductive argument for Christianity. This I have no problems with, and it is quite a quick-and-useful method when discussing the truthfulness of the Christian faith, but it is some distance from what the first presuppositionalists set out to do.

__________________
Steven Nemes
Phoenix, AZ

Good philosophy must exist, if for no other reason, because bad philosophy must be answered - C.S. Lewis

Yeah, this is gonna be fun to watch.

__________________
Seth Stark
Member, Communion Presbyterian Church (ARP), Irvine, CA
Biola University, Graduate Student, M.A. - Science and Religion
Seth's Blog

Labeling the presuppositional apologetic as fundamentalism seems to "poison the well" and is not conducive to a constructive discussion.

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Lance G. Marshall
Pastor
Georgetown, Indiana

I didn't argue that presuppositionalism was fundamentalist, but rather, I am arguing against what I call "fundamentalist presuppositonalism", like fundamentalist Baptists or fundamentalist Islam; very conservative presuppositionalism, basically, and I explained what conservative presuppositionalism is: the claim that Christianity is necessarily true.

Is there a form of presuppositional apologetics that doesn't make this claim? Can you give me an example of a presuppositional apologete who you would define as "non-fundamentalist"?

Like John Frame, who it seems to me has does not endorse the claim that Christianity is necessarily true; Francis Schaeffer is another example; Brian Bosse on this website is another example. They are what I would call more "liberal" presuppositionalists.

It seems like your whole argument against the necessary truth of Christianity is confused by your idiosyncratic definition of "Christianity," as:
"In such a world, there is no incarnation and no atonement; because there is no need, because there is neither of these things, there is no Christianity. Christianity is not true in this worldview because there is no sin and no Jesus of Nazareth who took on the sins of the world. So Christianity is not necessarily true."
If "Christianity" means the orthodox doctrines of the incarnation, atonement, and sinfulness of man (to require the two former)--and only these!--then many, I take it, will admit you are quite right. But so what? You haven't shown that Christianity by the more common meaning (e.g., including the existence triune God of Scripture), is not necessarily true, right?
Why you say that, if the presuppositionalist can prove the necessary existence of the triune God, then he still hasn't proven Christianity true at all, is odd. Isn't this merely because you have so reduced the meaning of "Christianity"?
Also, could you show us where CVT or Bahnsen contend that Christianity, in your meaning of the word, is necessarily true? E.g., that if God creates at all, he must create a world in which there is sin, incarnation, and atonement?
Perhaps I've misunderstood somewhere?

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Patrick
Covenant (OPC), Brighton, MI

For clarifications sake what you are labeling "fundamentalist presuppositional apologetics" is more often referred to as the "strong modal form of TAG". Your labels don't help because if there is either "liberal" presup./TAG (Frame) and fundi. presup./TAG(Van Til, Bahnsen) then what is just plain presuppositional apologetics/TAG?

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Noah
Calvin College (student)
CRC
Grand Rapids, MI

"a great deal of sense about the universe"? That's a pretty weak foundation to rest your apologetic on, and it puts you at a complete standoff when discussing the faith with Muslims, Mormons, Hindus or anyone else who thinks their philosophy "makes a great deal of sense about the universe".

I also don't see how your 'hypothetical world' proves anything about whether Christianity is necessarily true or not. If you're going to be true to presuppositionalism, then you have to realize that indeed such a world is impossible based on the presupposition of the triune God. Under other presuppositions, of course, such a world would be viewed as possible - but at the heart of presuppositionalism is the embracing of the fact that EVERYONE has root presuppositions, and subseuqent showing that any alternative to the presupposition of the Triune Godhead is impossible. Your argument really doesn't hold any water if you treat Van Tillian presuppositionalism correctly as it is actually practiced.

__________________
Todd K. Pedlar
member, First Congregational Church, (CCCC) Cresco, IA
http://inprincipiodeus.solideogloria.com
http://puritanwisdom.blogspot.com

"As God did not at first choose you because you were high, He will not now forsake you because you are low."
John Flavel in Keeping the Heart



Click to get: Board Rules -- Signature Requirements -- Suggestions?

What do you mean by the part I have underlined? And what do you mean by the other implication that no presuppositionalist has demonstrated the inconsistencies of non-Christian worldviews?

Ignoring the special pleading in your scenarios about "Christianity" that have already been pointed out, your arguments are defeatable by the well-grounded practitioner of presuppositionalism.

For example, playing off your contrived themes, one might ask...

Would a world with no sin be the best possible world for the common good?

Would a world with no sin be the best possible world for the greatest good?

The answers would lead to the inevitable head-on epistemological thrust of presuppositional approaches.

AMR

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Patrick
Member, PCA
Chandler, AZ
ReformedTheologyInstitute.com

I fear explanations explanatory of things explained.

I think that presuppositionalists like Van Til and Bahnsen have shown that the God of the Bible - compared with the various other personal and impersonal deities and philosophies on offer - is the only adequate foundation for the universe. People can invent other Gods - like the "Quadrinity" - to challenge that position, but one of the major problems with these is that we know they're invented. Hence presuppositionalists and other apologists can and should take Allah versus the God of the Bible (Yahveh) seiously, or Christian Theism versus Atheism seriously, but not Christian Theism versus the Quadrinity.

"For their rock is not is not as our Rock, even our enemies themselves being judges." I.e. Non-Christians have to presuppose the Christian God in order to make sense of the world, because every other "god" is an inadequate foundation, unlike "I AM THAT I AM".

The main problem I have with presuppositionalism, is, Can it be made comprehensible to the average man in the street? It's important that an argument - even a very sound one - must be understood in order to be effective. A "poorer" argument, e.g. Look at all the fulfilled prophecy in the Bible;the Bible must be true, can be more effective than a better presuppositionalist argument, if the person you are evangelising understands the argument.

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Richard
communicant member, FCoS
Perth, Scotland UK

His Name forever shall endure;
last like the sun it shall:
Men shall be blessed in Him,
and blessed all nations shall Him call (Ps. 72:17)

If the man in the street then claims that all the prophecies written in the Bible were in fact written after they occurred, then where do you go?

Presuppositional apologetics are not difficult to understand. Conversations that take place between a presup apologist and an unbeliever are normal, everyday conversations. No big jargon, no fancy word-games, nothing. It's a misunderstanding, I think, of presuppositional apologetics to think that the discussions are needlessly highbrow and intricate. They really needn't be at all.

Actually, the Quadrinity exception strikes at the very heart of a transcendental argument, because a transcendental argument must show that the denial of the transcendental premise is necessarily a contradiction in all possible worlds. Those are the rules, and Quadrinity shows that TAG does not live up to the demands of transcendental argumentation.

The reason why Quadrinity in particular is so effective is that it offers an alternative 'god' who still accounts for the "one and the many." Just as an aside, I don't think it's proper to appeal to the Trinity to explain "the one and the many" for two reasons. First, we don't really understand exactly how God is one and many, so there's no way we can transfer that knowledge to our general epistemology. Second, the epistemological problem of "the one and the many" concerns how people relate species to genus, which is not how the members of the Trinity are related. Thus, it is an equivocation.

__________________
Charlie Johnson
Downtown Presbyterian Church (PCA)
Greenville Presbyterian Theological Seminary, student

Steven,
You are also not understanding the foundation of presuppositionalism. Presuppositionalism is working out the philisophical implications for what the Bible claims. The Bible states that there is only one God and one way of salvation. That is the objective foundation of presuppositionalism. It is the Bible which tells us the nature of ourselves, the world, and the mess were in. If the Bible is true, then all other religions are false. All the presuppositionalist has to do is show the inconsistencies of any other religion which the Bible itself does an many occasions. See Acts 17, Psalm 115, Isaiah 45, etc. And if the Bible is true, then man is in fact made in the image of God, actually knows God in some way under the covenant of works, and has a twisted heart designed on contradicting the true God as much as he may get away with. Again, presuppositionalism is just working all those truths out philisophically when it defends the faith against other religions.

__________________
Patrick
MDiv, RTS Jackson
Pastor, Grace Presbyterian Church (OPC), Lisbon, NY

"He does well, that discourses of Christ; but he does infinitely better, that by experimental knowledge, feeds and lives on Christ." Thomas Brooks.
"Let us not please ourselves that we have deep understandings, but let us shew our understandings by our practice." Richard Sibbes

Is presuppositionalism "arguing for ..." anything? Mr. Van Til was developing a consistently reformed position across all disciplines of theology. You could not argue for the existence of God because God's existence is the axiom upon which the rest of your position rests. Mr. Van Til was developing a consistent Christian philosophy.

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JWithnell
Member Bethel OPC
Virginia
http://learningyesican.blogspot.com/

A note to my presuppositionists brothers; you are making me so proud and jelous at the same time. I have read the things you are writing but I can't condense them into words as clearly as you are doing on this thread. Todd, Pactrick, Charlie and you others are blessing my morning and strengthing my faith.

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Alan Hughes
PCA
Lake Zurich, Illinois

If you think I'm a Hyper-Calvinist, God planned that thought before the foundation of the Earth. If you try to tell me that God only planned some things and not all things, then your problem is with God not me.

Isn't this missing the one "presupposed" truth upon which presuppositionalism is founded? That being: the Bible is the true, revealed Word of God. The Quadrinity may try to account for the one and the many, but it fails the test of presuppositonalism, because it is not found in Scripture and is therefore a false description of God. What presuppositionalism presupposes is not the Triune God, but the Triune God of Scripture. Any other supposed god is false because it cannot be found in the Bible, which alone is our foundation upon which our religion is built.

How do you or would you argue for the truth and correspondence of Christianity?

__________________
John
Member
Christ Presbyterian Church (OPC)
Salt Lake City, Utah
www.christpres.net

Actually, no, that's not what Van Tillian presuppositionalism is. Van Til advocted a form of transcendental argumentation which originated with Kant and is heavily indebted to him. A transcendental argument does not proceed by pronouncing something to be true based on evidence or testimony, but by pronouncing it to be a necessary precondition for knowledge. I believe Van Til said something to effect of, "Unless God is back of everything, you can know nothing." He did not argue that Christian theism is true because the Bible says so, but because the alternative is self-defeating, not providing a sufficient epistemological foundation.

This is where confusion sets in. Evidentialist apologists argue for the existence of God and the trustworthiness of the Bible. Van Til completely changed the nature of apologetics by suggesting that apologists had been setting their sights too low and that both God and Scripture could be proved simply by the impossibility of the contrary. He argued that the God of the Bible was the only suitable explanation for the intelligibility of the world, and that all other worldviews only existed by being inconsistent with their own fundamental presuppositions.

So, to summarize, Van Tillian presuppositionalism is not about taking the Bible as our presupposition. It is about positing the God of the Bible as the only presupposition that successfully accounts for intelligibility. This is the philosophical definition of presupposition within a transcendental framework. Really, one cannot correctly understand Van Til without understanding something of Kant and the development of German Idealism.


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Oh, I just remembered, in the Bahnsen-Stein debate, Bahnsen specifically denies that he is arguing his position "because the Bible says so."

Without making a statement for or against what you have said, I will have to wait until I can review Van Til to see if I agree with what you have said.

Thank you, though, for the reply.

But Gordon Clark does ... would he be considered a fundamentalist in this category?

I will respond to all of your posts later today; at the moment I've got somewhere to be.

I just read your post... 18, huh?

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Michael Masztal
Ruling Elder, Chapel By The Sea, ARP
Melbourne Beach, FL

I'll just state in passing (since I have little time at the moment) that objections like these are what have convinced me to be a "Common sense presuppositionalist" ("presuppositional Thomist" is too vague--so I've dropped the term).

I do think that the Kantian assumptions of presuppositionalism do need to be challenged--methinks a Reidian epistemology accounts for our knowledge better.

__________________
Philip
Potomac Hills Presbyterian Church (PCA) Leesburg, VA
Attending Reformed Presbyterian Church, Lookout Mountain, GA
Student Covenant College

The Importance of Being Orthodox

I too am leaning toward a Reidian/common sense presuppositionalism in light of some quibble's with the strong modal form of TAG, what Steven has labeled "Fundamentalist Presuppositionalism" (I disagree with his label). It also seems that Michael Horton leans this way as well, see his article here(you need to be a subscriber to Modern Reformation to read it): http://www.modernreformation.org/def...=AutRes&var5=1 It basically just shows a leaning towards recovering forms of common sense realism.
There are also some articles over at Triablogue pertaining to this topic as well, see especially this one: Triablogue

Is this unaided common sense or regenerated common sense?

Steven,

I think terms like "fundamentalist [fundy] presuppositionalism" might best be reserved for "inside" conversations, just as you wouldn't call a Roman Catholic a papist to his face unless you intended to anger him. Although, I do believe that "fundamentalist presuppositionalist" does sound less offensive than "papist."

As I told you recently, I'm straying somewhat from "orthodox" Van Tillian presuppositionalism. This is foremost because I reject the Van Tillian notion that we have to argue for the impossibility of an unbelieving worldview. I'll get to that in a second. First, though, I believe there's a problem with your example that Christianity is not necessarily true: a presupper probably wouldn't say that "Christianity" entails the all the specific religious-historical events that take place in this world. They might make "Christianity" less specific than that, referring only to the ontological Trinity as the necessary basis of knowledge, but in that case it isn't true that the Bible in toto is necessary for knowledge. Presumably, a presupper could argue both for the necessity of the ontological Trinity and the necessity of revelation for knowledge, but in this case, again, the specific content of the Bible is not necessary for knowledge, just the facts of Trinity-ness and divine revelation.

In any case, while I don't think you have a perfect critique of "orthodox" presup, I do think that it can be critiqued. IMO to say that every verse of the Bible is necessary for knowledge is a bit absurd, but that once the case for Christianity is reduced to an argument for the necessity of Trinity and of divine revelation, then there is no root disagreement with evidentialists.

Anyway, regarding what I said above: "I reject the Van Tillian notion that we have to argue for the impossibility of an unbelieving worldview." There are basically two reasons Van Til gives for this if I'm not mistaken: (1) arguing probabilistically would make possibility more ultimate than God (which is according to CVT a pagan concept), and (2) giving unbelievers any probability would give them some sort of excuse for their unbelief, but they are to be "without excuse."

(1) is vague. It also doesn't realize that probabilistic argument is made not because of some ontological assumptions about the universe - e.g., that some substance or void called "possibility" was the birthplace of God by some demiurge -- but because of humans' limited perspectives. We don't know things with philosophical certainty, and therefore we cannot claim to know things with philosophical certainty, because we are finite.

(2) is simply false. It is not the case that unbelievers receive some excuse just because some particular apologist does not make his case strongly enough. If it is true that all unbelievers are without excuse for not believing in God, then it follows that their being without excuse must in some form be non-inferential; otherwise anyone who failed to hear an apologist's specific argument for the certainty of God's existence is without excuse. And if their being without excuse is non-inferential, then it follows that the apologist is not giving them excuse by failing to give them the inferential reasons why God must exist.

I still have presuppositionalist tendencies and am appreciative of them, e.g. believing that Christians are obliged to accept the Bible on its own authority, but I have taken a different stance regarding the permissibility of evidences and natural theology. I'll make a new thread on that after I'm done making my way through this thread.

-----Added 8/12/2009 at 03:49:37 EST-----

Hi, Todd. Hope you're doing well.

I think your criticism establishes that other people will disagree, but not that they will be correct or untouchable in their disagreement. To be quite honest, this objection of yours has the same structure as the Roman Catholic objection against "private interpretations" of Scripture, e.g. "How do you know your interpretation's right? Thousands of other denominations would disagree with you."

The answer is that this doesn't put us at a standoff, for there still is a place to look for the answers. Muslims, Mormons, and Hindus can still have holes in their philosophies and inconsistencies with the real world, and that is what the Christian apologist should look for.

Interestingly, the standoff objection is usually applied to presuppositionalists.

If it is available, you give him evidence to show that they were written earlier.

This leads me to another problem with "orthodox" VTian presup: the premise that no evidence can be commonly interpreted by people of different worldviews. Even in one of the most extreme examples VT gives, the resurrection of Christ, he demonstrates that they share a common interpretation to some extent: in his trialogue (is that a word?) with Mr. Gray, Mr. White, and Mr. Black, he has Mr. Black agree with Mr. Gray that Jesus rose from the dead after Mr. Gray presented some evidences, and then Mr. Black interprets it as a naturalistic phenomenon. Even in this situation, you have both Mr. Gray and Mr. Black in agreement on the fact of Jesus's rising from the dead -- and the only problem is Mr. Black's secondary distortion of the fact. Van Til in examples like these establishes the existence of such facts but elsewhere denies them.

I'm not sure these can be sharply distinguished. Take the existence of objective morals, for existence. An evidentialist might say that the existence of moral laws which implies a moral Lawgiver, whereas a presupper might say that given the Christian worldview morals make sense (because a moral Lawgiver makes sense) but given an atheistic-empiricist worldview they do not (because a moral Lawgiver does not). In the presupper's argument, you have him applying the conclusion of the evidentialist argument to each worldview and showing how one worldview remains consistent while the other doesn't.

But this is simply to say that the presupper is using the exact same argument as the evidentialist, but also is assuming his starting point. I am going to clarify this difference (or rather this similarity) on a new thread I am going to make entitled, "A Synthesis of Apologetics."

__________________
Ben Maas. . . . .Facebook
In college, attending First Presbyterian Church (PCUSA), Ada, OH, and
Belle Center Reformed Presbyterian Church (RPCNA), Belle Center, OH
When at home, attending Covenant Presbyterian Church (OPC), Mansfield, OH

“Prayer is as natural an expression of faith as breathing is of life.”
-Jonathan Edwards-

Benjamin,

Please define your term "philosophical certainty", and explain its relationship to finitude.

Thanks,

__________________
Adam B., Wine Country, California, PCA

"I fear not to hold with Junius, de Politia Mosis cap. 6, that he who was punishable by death under that Judicial law, is punishable by death still; and he who was not punished by death then, is not to be punished by death now."

If we know something with philosophical certainty, then that means that we have no possible reason to doubt it. For instance, I can know with certainty that I exist because even if I doubt my existence, it still implies the existence of a doubter.

This does mean that we cannot know with philosophical certainty that (e.g.) a computer screen is in front of us. But I think this demonstrates just how high (too high IMO) Van Til is raising the bar when he asserts that the Christianity can be argued as true with certainty.

Since we are finite, it follows that we cannot know everything, and therefore in most of our situations there could be some proposition that we don't know that could potentially disprove what we think we do know. For instance, take the "evil demon" and sensory experience. Because we are not omniscient, we do not know with certainity that our senses correlate to an external reality.

Does this mean we should wallow in skepticism? No. But it does mean that we need to be careful about what we assert to know with certainty.

Thanks for asking, Adam.

Ben,

You are welcome for asking!

So, if I understand you correctly, you do not believe that certainty is attainable because of finitude; is that correct?

Cheers,

Yessir.

Quote from Ben
Does this mean we should wallow in skepticism? No. But it does mean that we need to be careful about what we assert to know with certainty.

But surely Van Til and Bahnsen taught that all men know the God of the Bible with certainty; the only reason they deny this or aren't as aware of this as they should be is sin. Bahnsen sought to make men aware - by the blessing of God on his apologetic - of this fundamental knowledge of God, without which a man could not make sense of anything. It's not finitude that makes men deny the certainty of the God they know, and by which they interpret reality, but sin.

It's the knowledge of God that makes any knowledge about anything else by anyone, regenerate or unregenerate, possible.

The knowledge they taught was non-inferentially obtained. It had to be; otherwise, many people would be "without excuse." And since it is non-inferential, there is no moral requirement for an apologist to argue for the certainty of God's existence. The apologist can make unbelievers aware of this knowledge with probabilistic arguments.

So, in your earlier post, you asserted that:

In follow up to this definition, I have a few more questions:

1. Do you believe that God is truth and reason itself?

2. Do you believe that anyone knows God?

3. Is the knowledge of God doubtful or certain?

4. If the knowledge of God is doubtful, how do you reconcile God as Truth with knowledge of God as doubtful?


Cheers,

Adam,

You are magnifying the importance of the distinction between a non-inferential knowledge of God and the ability to prove this discursively. I am stating that because we have the former, the latter is not morally required by the apologist.

I apologize for speaking so ambiguously before. I should have said that I believe certainty in the knowledge of God (non-inferentially) is attainable by humans, but an ability to express this via rational argumentation with certainty is not, because of finitude.

Although, even if I were wrong in the ability of humans to express a certain argument for God's existence, it wouldn't really matter so long as it is not held that the apologist is committing a moral error in using a probabilistic argument.

1. Yes; and if it would be wrong to set God and reason as equivalent, then I would still say that reason has its ontological basis in God.

2. Yes.

3. It is certain but non-inferential.

I have magnified nothing; please attempt to read what I have written, and not read motivations into my questions.

If one quotes from Holy Scripture using rational argumentation, is it certain?

I apologize if I read motivations into your questions. What I was trying to say is that I was speaking ambiguously, and your question brought to my mind an important distinction that clarified my thought.

Yes (assuming the Scripture passages are used appropriately, without fallacies), and I would say that this is because we can know that Scripture is authoritative non-inferentially.

Gotcha

Ben,

Can you please define what you mean by knowing a proposition non-inferrentially.

Also, are you saying that non-inferrential knowledge does grant certainty (at least of the proposition "Scripture is authoritative" if not others)?

Cheers,

By "knowing a proposition non-inferentially," what I mean is that the proposition is known apart from separate evidences, or apart from a syllogism (inference). For instance, we can know non-inferentially that there is a computer screen in front of us. (I'm not saying we can't know it inferentially, though.)

And yes, I am saying that it does grant certainty.

One of the examples that Van Tillians typically give, and that is central to the entire presuppositional apologetic, is from Romans 1:18ff., in which it is claimed that all men universally have some type of immediate knowledge of God.

long reply...

To CatechumenPatrick: Proving that the Christian God exists does not mean Christianity is true; that's obvious, because our God could exist and simply have not revealed himself in scripture or not have come to Earth in the form of man. And yes, if there is no atonement and incarnation, there is no Christianity; unless you are willing to call liberals who don't believe in either but believe the gospels are wise fictional literature just as true Christians as you and I.

What is the difference between plain presup and strong modal TAG? What other form of TAG is there, besides "Christianity is a necessary precondition for logic, morality, and science"?

That is just plainly false; how does Hindu religion explain the natural human inclination towards worship of something greater than themselves (for an example) in a way that is any more satisfactory than Christianity?

Do you really think that a world where God creates man but doesn't decree him to sin is impossible? How is that impossible? You are obligated to claim that God decrees men to sin necessarily; there is no possible world where God doesn't decree men to sin---why on earth should anyone believe that? It is contrary to common sense and also a very strange limitation for a God who is supposedly omnipotent.

I hereby invite you, and the whoever else on the Puritan Board who is willing, to demonstrate beyond reasonable doubt, the inconsistency and contradiction in not only every worldview currently believed on earth, but also every possible worldview; a task like this, if completed, would show the necessity of the Christian worldview (but also prove a lot of things which seem quite possible impossible (as I noted above)).

There is no special pleading anywhere in post; I'd ask you to point it out.

I don't know the purpose of those questions, maybe you can explain what you mean.

This isn't an answer at all to what I've wrote; but also, the fact that the Quadrinity god was supposedly made up doesn't mean it does not exist. It surely seems possible (there is no contradiction in it), so even that is a claim against the supposed necessity of the Christian God.

Proving the inconsistencies of other religions does not prove Christianity true.

I wouldn't know. Maybe some of the classical arguments, with a bit of evidentialism thrown in.

If you reduce Christianity to just the existence of the trinity, then anyone who believes in a Trinity but does not believe in justification by faith, or by works, or justification at all, or an incarnation, or an atonement, etc., is a Christian.