1 Corinthians 9:21

Likewise when Paul was with Gentiles he behaved as a Gentile. This would have involved eating what they did, among other things.

The references to law in this verse may be confusing. In describing Gentiles as being without law, Paul did not mean that Gentiles are totally lawless (cf. Romans 2:14). He meant they were not under the Law of Moses as the Jews were (1 Corinthians 9:20). Paul wanted his readers to understand that even though he did not observe the Mosaic Law when he was with Gentiles (Gr. anomos) he was still under God’s authority (ennomos). As a Christian he was not under the Law of Moses, but he was under the Law of Christ (cf. Galatians 6:2). The law of God for Jews before the Cross was the Law of Moses, but His law for Christians in the present age is the Law of Christ. The Law of Christ is the code of responsibilities that Christ and His apostles taught, which the New Testament contains. Some of the same commands are in the Mosaic Law though the codes, the Mosaic Law and the Law of Christ, are not the same. [Note: Femi Adeyemi, "The New Covenant Law and the Law of Christ," Bibliotheca Sacra 163:652 (October-December 2006):438-52, correctly equated the Law of Christ with the New Covenant Law (cf. Jeremiah 31:31-34).]

"This is one of the most difficult sentences in the epistle, and also one of the most important, for in it Paul shows how the new relation to God which he has in Christ expresses his debt of obedience to God." [Note: Barrett, p. 212.]