do you believe all the Christians in Judea were depending on the blood of goats and bulls for forgiveness of sin, and that this is the message they were preaching, up until the apostles first heard the true gospel from Paul?
The usual refrain "What does scripture says?"
Even in Acts 21, we still see James and the elders telling Paul to use money to sponsor the shaving of head ceremony, in order to show that as a Jew, he is still following the Law.
Acts 15 is a distraction. As I have said elsewhere, James only decided that Gentiles who believed will be exempted from the Law of Moses. The Jewish believers must continue in the Law of Moses even after the Council, and a reading of Acts 21 showed that the Jews who believed were still zealous for the Law. (Acts 21:20-25)
What saith the scripture?