My dear friend. You have to look at the Bible as a whole. In order to come up with your interpretation on Galatians 2:7, it would have to be read in the vacuum of space with no other surrounding verses. As Christians we need to read more the whole chapter when reading a difficult a verse and we need to ask God the Father for His Spirit to give us the understanding, too. So I would highly encourage to prayerfully reread Galatians chapter 2 entirely and reflect on the full context that is given. I believe you are getting caught up on the archaic wording in the KJV. Granted, this is not an error in the KJV. As you may know, I am a strong KJV defender, and I am no fan of Modern Bibles, but they can sometimes be helpful of fleshing out the archaic wording in the KJV sometimes (When the wording does agree). This is one of those instances that is good to read the whole chapter in a Modern Translation to understand what is going on (and then switch back and re-read the whole thing again in the KJV). So please try reading the whole chapter first in the NLT, then go back to the KJV to see how they match up.
Galatians 2:7 is merely referring to the scope of the chosen audience by Paul and Peter. If you look at verse 8 (KJV) more closely it talks about how God wrought effectually in Peter to the apostleship of the circumcision, the same was mighty in me toward the Gentiles. This helps explain verse 7 in the fact that it was the working of God was moving to be more effective for the cause of the gospel for Peter when he encountered the Jews, and Paul was more effective for the gospel when he encountered the Gentiles.
Furthermore, if you keep reading in Galatians 2, Paul said that Peter did not walk according to the truth of the gospel (Galatians 2:14) (See: Galatians 2:11-14).
In addition, we learn that Paul preaches the gospel to the Jews and when they did not accept it, and the Gentiles in that audience did instead, then Paul decided at this point to focus on going to the Gentiles. It was not that Paul all of sudden switched gospels or something.
Acts 13:42-49
42 “And when the Jews were gone out of the synagogue, the Gentiles besought that these words might be preached to them the next sabbath. 43 Now when the congregation was broken up, many of the Jews and religious proselytes followed Paul and Barnabas: who, speaking to them, persuaded them to continue in the grace of God.
44 And the next sabbath day came almost the whole city together to hear the word of God.
45 But when the Jews saw the multitudes, they were filled with envy, and spake against those things which were spoken by Paul, contradicting and blaspheming.
46
Then Paul and Barnabas waxed bold, and said, It was necessary that the word of God should first have been spoken to you: but seeing ye put it from you, and judge yourselves unworthy of everlasting life, lo, we turn to the Gentiles.
47 For so hath the Lord commanded us,
saying, I have set thee to be a light of the Gentiles, that thou shouldest be for salvation unto the ends of the earth.
48 And when the Gentiles heard this, they were glad, and glorified the word of the Lord: and as many as were ordained to eternal life believed.
49 And the word of the Lord was published throughout all the region.“
If this is not enough, Peter even said that Paul had written unto those Jewish believers he was writing to, as well.
2 Peter 3:15
“And account
that the longsuffering of our Lord
is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you;”
