The law does not save. The Gospel is the power of God unto salvation. But this did not stop certain ancient heretics from peddling the notion that the Law of Moses was necessary unto salvation. Paul and Barnabas return to Jerusalem in order to put the issue to rest. Ultimately, the biblical Gospel of salvation by grace alone through faith alone in the finished work of Christ alone is upheld by the Apostles much to the delight of both genuinely saved Jew and Gentile alike.