Are you reading Acts 21:19-25 literally?
19 And when he had saluted them, he declared particularly what things God had wrought among the Gentiles by his ministry.
20 And when they heard it, they glorified the Lord, and said unto him, Thou seest, brother, how many thousands of Jews there are which believe; and they are all zealous of the law:
They rejoiced at what God was doing among the Gentiles, and they reaffirmed in Acts 21:25 that Gentiles do not have to follow physical circumcision and the Law of Moses, as determined in Acts 15.
What they were unhappy about is that there are Jews who were listening in to Paul preaching to the Gentiles, Galatians 5:2
Galatians 5:2, KJV: "Behold, I Paul say unto you, that if ye be circumcised, Christ shall profit you nothing."
and some of these Jews were also following that same teaching (Acts 21:21), even though Acts 15 only exempted Gentiles, nothing was said by James, about whether Israel also needed to follow the Law, the latter was not even on the agenda.
19 And when he had saluted them, he declared particularly what things God had wrought among the Gentiles by his ministry.
20 And when they heard it, they glorified the Lord, and said unto him, Thou seest, brother, how many thousands of Jews there are which believe; and they are all zealous of the law:
They rejoiced at what God was doing among the Gentiles, and they reaffirmed in Acts 21:25 that Gentiles do not have to follow physical circumcision and the Law of Moses, as determined in Acts 15.
What they were unhappy about is that there are Jews who were listening in to Paul preaching to the Gentiles, Galatians 5:2
Galatians 5:2, KJV: "Behold, I Paul say unto you, that if ye be circumcised, Christ shall profit you nothing."
and some of these Jews were also following that same teaching (Acts 21:21), even though Acts 15 only exempted Gentiles, nothing was said by James, about whether Israel also needed to follow the Law, the latter was not even on the agenda.
Translation: "The Mosaic Law is done, but the Moral Law - the Ten Commandments - remains."