It is an actually interesting idea that the community of God's called out ones is the basis for "gathering" or "synagoging" together to pray, sing, hear the Scriptures read, and have them commented. I would contest that the sunagogue was a reflection of the temple, and not aside or instead of the temple, since all the elements of temple worship are CRITICAL to our worship today - i.e. a high priest, atonement, sacrifice, sacramentaology, etc. The Temple's destruction was not a removal of the temple, but a transferrence of the realities completed in Jesus Christ that still continue for God's elect people, if I might say - the "synagoging ones", or those who "synagogue together, as the Aposlte James states.
Interesting...
I don't know if any of you bothered to read this lengthy thread that occurred a while back: http://www.puritanboard.com/f67/synagogue-worship-musical-instruments-regulative-principle-13358/
It is clear to me that God's people were commanded to assemble together to worship one day in seven. The principle is not only in the Law but I would argue this is a Creation Ordinance with the Sabbath.
On my very basic defense of the RPW: Why the Regulative Principle of Worship? | SoliDeoGloria.com
In a nutshell, fallen man needs Divine Institution because his heart is deceitfully wicked.
This is why discussions of the RPW are inevitable and I commend bradofshaw for noting this fact.
What you note, Matthew, seems to me to be indispensible that the idea of assembling is clearly commanded and understood. What I think we need to recognize, additionally, is the idea of the targum. That is to say that not all traditions were necessarily simply the traditions of men simply because men were those who put the traditions in place. We even note Biblical authors using this mode of teaching and expansion upon the Scriptures. In one sense, even the Septuagint (which Christ quotes from) is an interpretation (or targum) of the original language.
It is fascinating, for instance, to see tremendous Biblical insights by some Rabbis centuries before Christ who taught that when Messiah came that temple sacrifices would cease.
This is a round-about way of saying that I think Synagogue is a Biblical concept but that the elements of it were recognized by God's people and, more specifically, the elders in the OT assembly. As I think of my Old Covenant forbears as essentially worshipping the same substance as I, I also must conclude that God providentially guided Rabbis and elders in the formation of elements and forms in synagogue worship.
That said, however, I'm not sure we're going to be able to "proof-text" all the decisions as to circumstances but you can certainly find warrant for the elements therein.