Hello Clayton,
If you're still looking in, that's a good question: how does one interpret 1 John 2:2?
And he is the propitiation for our sins: and not for ours only, but also for [the sins of] the whole world.
I believe John wrote this later in his life, perhaps around the year 90 A.D., when he was reportedly living in Asia Minor/Ephesus, and there were Gentiles in the area as well as Jews. We know he surely had the Jews in mind writing this epistle, as well as Gentiles, and with the former it is well known they were long indoctrinated that only they would be saved when Messiah came — and the Gentiles condemned. The Jews reading or hearing this epistle would know very well what John meant: that
not only they but Gentiles in the world outside Israel were to be included in the propitiation the Redeemer offered unto God.
In like manner John the Baptizer knew exactly what he was saying when he cried out, "Behold the Lamb of God, which taketh away the sin of the world." (Jn 1:29) Likewise the Lord Jesus, when He said, "For God so loved the world, that He gave His only begotten Son..." (Jn 3:16) To the Jewish mind this
expanded vision (albeit foretold by the prophets; Cf. Isa 42:6; 49:6; Ps 22:27; Mal 1:11, etc) of God's plan of salvation was not readily accepted by the Jews. To wit: When Paul in Acts 22:21 told the assembled Jewish crowd that the Messiah had said to him. "Depart: for I will send thee far hence unto the Gentiles," their reaction was, "Away with such a fellow from the earth: for it is not fit that he should live." It was an unspeakable travesty of the ways of God (to them) that such a thing should be.
Little wonder John — who had an apostolic commission to the Jews (even while he spoke to and lived among the Gentiles) — continually reiterated this point to them: not only for you, but for the elect in the whole world beyond Israel, has the Propitiation been made.