1 Cor 9:19-22 says (BSB):
19 Though I am free of obligation to anyone, I make myself a slave to everyone, to win as many as possible. 20 To the Jews I became
like a Jew, to win the Jews. To those under the law I became like one
under the law (though I myself am not under the law), to win those
under the law. 21 To those without the law I became like one
without the law (though I am not outside the law of God but am under
the law of Christ), to win those without the law. 22 To the weak I
became weak, to win the weak. I have become all things to all people
so that by all possible means I might save some.
[Note, the phrase, μὴ ὢν αὐτὸς ὑπὸ νόμον = even though I am not under the law, is missing from the TR and the KJV. For a discussion about this, see UBS5 and its references.]
Paul here is discussing his approach to evangelism - he adapts his methods culturally without compromising principle. The question here is, What does "though I am not outside the law of God but am under the law of Christ", mean?
First let us identify some of Paul's euphemisms:
- "Jews" are easy to identify
- "those under the law" are presumably (as distinct from Jews by birth) people, Gentiles who choose to burden themselves with minute keeping of the Torah. Ellicott says: "Those spoken of as “Jews” are, of course, Jews by birth and religion; those “under the Law” are probably proselytes to Judaism. In neither case do they mean Christian converts, for the object of St. Paul’s conduct towards those of whom he here speaks was to win them to the Faith of Christ. He himself was no longer “under the Law” being a Christian (Galatians 2:19)."
- "those without the law" are pagans who do not know the law, the Torah.
... and so forth. Paul's parenthetical statement is supremely important to understand his Gospel. Many people say that as Christians we are free of the law - in one sense that is true, but it does NOT mean that Christians are lawless nor antinomians. Christians are bound by the "law of Christ" (1 Cor 6:21, Gal 6:2), or, "Law of God" (Rom 8:7, 1 Cor 9:21), or, "Law of the Spirit" (Rom 8:2), or, "My laws" (Heb 8:10, 10:16), or, "Law of Faith", or, “Royal law” (James 2:8), or, “Law of liberty” (James 1:25, 2:12), etc.
Thus, Paul could honestly say that he was not "under the law" (Torah), "I am not outside the law of God but am under the law of Christ".
I recently did a complete survey of every instance in the NT of the word νόμος = law. In all instances, the word invariably means the law that is associated with a covenant: most times the old covenant, or what is loosely described as the Torah. However, as pointed out above, it is also used as the law associated with the New Covenant and is variously described as: the "law of Christ" (1 Cor 6:21, Gal 6:2), or, "Law of God" (Rom 8:7, 1 Cor 9:21), or, "Law of the Spirit" (Rom 8:2), or, "My laws" (Heb 8:10, 10:16), or, "Law of Faith", or, “Royal law” (James 2:8), or, “Law of liberty” (James 1:25, 2:12), etc.
One of the best summaries of the New Covenant, even using identical language and quoting from the the language in the establishment of the Old Covenant (Ex 19-23) is found in 1 Peter 1, 2.
- The promise: Salvation by grace through the promised Messiah, 1 Peter 1:3-12, 20,
- Moral Requirements: holiness (1 Peter 1:15), Purity (v22), Obey the truth (v22), love (v22), “rid yourselves of all malice and all deceit, hypocrisy, envy, and slander of every kind” (1 Peter 2:1), abstain from sinful desires (1 Peter 2:11), submit to civil authorities (v13-17), see also Rom 13:1-7, etc.
- Sacrifice: Blood of Jesus, 1 Peter 1:18, 19
- Purpose: “But you are a chosen people, a royal priesthood, a holy nation, God’s special possession, that you may express the praises of him who called you out of darkness into his wonderful light … Live such good lives among the pagans that, though they accuse you of doing wrong, they may see your good deeds and glorify God on the day he visits us.” 1 Peter 2:9, 12
It is this law of Christ, God, faith, etc, that binds Christians, by the miraculous power of the Spirit (Rom 8:2), to be the sort people that display the righteousness of God (Rom 1:17, 3:5, 22, 6:13, etc). Thus, while Paul was under the law (of Torah) he was under the law of Christ.