When Paul arrived in Jerusalem, James, the Lord’s brother, spoke with him, revealing some misinformation that was going around concerning Paul,
“You see, brother, how many myriads of Jews there are who have believed, and they are all zealous for the law; but they have been informed about you that you teach all the Jews who are among the Gentiles to forsake Moses, saying that they ought not to circumcise their children nor to walk according to the customs. What then? The assembly must certainly meet, for they will hear that you have come” (Acts 21:20-22).
The Jews could still walk in the customs that they had gained through the Law of Moses, such as circumcision, even as other nations walk in their customs, so long as those customs do not contradict the Law of Christ. Paul did oppose those who thought that people needed to keep the Law of Moses to be saved, but there is plenty about the Law that can still be done without violation of the Law of Christ.