Acts 15:19-21 and Acts 21:20-25
This is about the new Gentile converts and the new Jewish believers wanting to make Gentiles immediately be circumcised and follow every law of Moses. James says let's not make this a burden/yoke around the new believers necks. Let's start with enforcing only 4 of Moses's laws and they will hear the rest of Moses's laws every sabbath when they are in the synagogue. So this shows even after Christs death His apostles were following laws and enforced them on new believers. But based on their judgement they just didn't want to overwhelm new Gentile believers with all the laws at once.
19 Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God: 20 But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood. 21 For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day.
James is saying that the new Gentiles should start by following 4 Old Testament laws. If the law is done away with, why would they not only allow the new Jewish converts to be zealous for the law but also tell the new Gentile believers to start with following 4 Old Testament laws?
Then, in Acts 21 the plot thickens!
All the Jewish believers in Jerusalem are ticked at Paul because they thought he was telling the Jews and gentiles in Antioch to turn away from Moses(law). Paul then undertakes a vow to show them it was only the new gentile believers he was trying to gradually introduce into the law so there was not a heavy burden on them. But the Jewish believers needed to follow the law immediately.
“When they heard this, they praised God. Then they said to Paul: “You see, brother, how many thousands of Jews have believed, and all of them are zealous for the law. They have been informed that you teach all the Jews who live among the Gentiles to turn away from Moses, telling them not to circumcise their children or live according to our customs. What shall we do? They will certainly hear that you have come, so do what we tell you. There are four men with us who have made a vow. Take these men, join in their purification rites and pay their expenses, so that they can have their heads shaved. Then everyone will know there is no truth in these reports about you, but that you yourself are living in obedience to the law. As for the Gentile believers, we have written to them our decision that they should abstain from food sacrificed to idols, from blood, from the meat of strangled animals and from sexual immorality.””
Acts 21:20-25 NIV