Because of this new covenant, the New Testament teaches us that circumcision is not necessary for our personal salvation. It wasn't necessary for acceptance by God in the Old Testament. Paul gives some teaching to the Corinthians and the Galatians about the place circumcision has in our relationship to Jesus Christ. He should not become uncircumcised. He should not be circumcised.
Circumcision is nothing and uncircumcision is nothing.
Keeping God's commands is what counts. For in Christ Jesus neither circumcision nor uncircumcision has any value. The only thing that counts is faith expressing itself through love. These verses are not to be taken as a slam against circumcision. Paul is saying to the Galatians and Corinthians that circumcision is not a ticket to heaven.