(Acts 15:28-29) Why does James add these requirements, if they are no longer under law?

CLAIM: James says, “Therefore it is my judgment that we do not trouble those who are turning to God from among the Gentiles, 20 but that we write to them that they abstain from things contaminated by idols and from fornication and from what is strangled and from blood” (Acts 15:19-20). If the apostles claimed that Gentiles are not under law, then why did James add these prescriptions?

RESPONSE: James was not including these stipulations as necessary for salvation. Instead, he was including these for a missiological principle. That is, as one of the central apostles for the Jewish people, James was requesting that these Gentile believers abstained from these particularly offensive practices. Idolatry, fornication, and bloody meat were particularly offensive to the Jews. Therefore, James asked that the Gentile believers would avoid these sorts of things.