Died to the Law
Gal 2:19,20 For through the law I died to the law so that I might live for God. I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me."
Likewise Paul writes of the Christian life, "now we have been released from the Law, having died to that by which we were bound, so that we serve in newness of the Spirit and not in oldness of the letter." Rom 7:6
The oldness of the letter is the bondage to the keeping of the customs and particular regulations one derives from the Law of Moses.
"He has made us competent as ministers of a new covenant— not of the letter but of the Spirit; for the letter kills, but the Spirit gives life." 2Cor 3:6
Jesus' ministry likewise revealed the deadness of bondage to the regulations which the Jews derived from the Law. Like he was often rebuked for healing people on the Sabbath. For as the Law commanded rest on the Sabbath, by way of regulation the Jews derived the idea that it was in violation of the Sabbath to heal. And yet healing was actually consistent with the Spirit of the Sabbath - giving rest and relief to the suffering.
So also to allegedly keep themselves pure, the Jews derived a regulation which prevented them from eating with Gentiles, though the Law had no such regulation. But in doing so they violated the Spirit of the Law - to love your neighbor as yourself. And this was especially an issue with Christians - as it broke Christian fellowship over an illegitimate issue.
You can't really live to God until you die to the legalism. Furthermore, what is relevant about the Christian life is not the Christian, but Christ who dwells in the Christian. "To (the saints) God has chosen to make known among the Gentiles the glorious riches of this mystery, which is Christ in you, the hope of glory." Col 1:27 So also Jesus said, "I came not to do my own will, but the will of Him who sent me." John 6:38 This is contrast to Peter's fear of man. People who are afraid of what others will think of them are too concerned for themselves. The Christian lives for Christ, not for themselves. "He died for all, that those who live should no longer live for themselves but for him who died for them and was raised again." 2Cor 5:15