Paul broke the covenant of God regarding circumcision.

God of the Old Testament says about circumcision...

Genesis 17:14

Any uncircumcised male, who has not been circumcised in the flesh, will be cut off from his people; he has broken my covenant."

Lets see what Paul says about circumcision...

1 Corinthians 7:19

Circumcision is nothing and uncircumcision is nothing. Keeping God's commands is what counts.

Paul fails to realize that to keep circumcision is to keep God's law and he is breaking it.