True, Christians are not under the Law Covenant as Paul wrote in Galatians 3:24. The Law Covenant was made only with the nation of Israel. Paul was explaining to Jews who converted to Christianity that they specifically were not under the Law any more. Let us now consider your 1 Corinthians question.
1 Corinthians 7:19 (NKJV), “Circumcision is nothing and uncircumcision is nothing, but keeping the commandments of God is what matters.”
Circumcision was established before the Law Covenant and was not part of the Law. God told Abraham to circumcise himself, his male family members, and the males of his household (including his servants) in Genesis 17:9-14. All male Jews were to be circumcised because they were part of Abraham’s offspring. But what commandments was Paul writing about in Corinthians?
The principles of God’s commandments are discussed in many New Testament scriptures. 1 John 3:22-24, “…this is his commandment, that we believe in the name of his Son Jesus Christ and love one another, just as he has commanded us. Whoever keeps his commandments abides in God,…”
A Pharisee asked Jesus what the greatest commandment was. “‘Teacher, which is the great commandment in the Law?’ And he said to him, ‘You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment. And a second is like it: You shall love your neighbor as yourself. On these two commandments depend all the Law and the Prophets.’” Matthew 22:36-40. Thus, we are commanded to love God, Jesus, and our neighbors..
Who specifically are our neighbors?
1 John 4:20-21, “If anyone says, ‘I love God,’ and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen. And this commandment we have from him: whoever loves God must also love his brother.”
Jesus explained our neighbors even include our enemies. Matthew 5:43-44, “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ But I say to you, Love your enemies and pray for those who persecute you”.
To summarize, if we think ourselves Christians, we must love God in word and deed. We show our love of God by obeying God’s principles in the Bible. God’s commandments teach us to love our brethren in our worldwide Christian family, to love our neighbors as ourselves and to love even our enemies. How can we attain to this state in our hearts? Only by changing our characters and natural tendencies and letting ourselves be renewed through the power of the Holy Spirit.
If we do not speak and act out of love, we cannot be God’s ambassadors, and if we say we are, we are liars.