What does Acts 15:10 mean?

Peter is speaking to a council of apostles and elders of the Jerusalem church. They are discussing whether Gentiles need to be circumcised and follow the Mosaic law. In other words, does a person need to become a proselyte to Judaism before they can receive salvation from Jesus? Peter has reminded the group that he witnessed the Holy Spirit indwell a house filled with Gentiles. Some of those Gentiles had worshiped the Jewish God, but none were converts to Judaism (Acts 15:1–9).

The issue has come about because of a disagreement between Paul and Barnabas and Jewish Christians of the sect of the Pharisees. Pharisees not only enforced the Mosaic law, but also added to it. Jesus said, "They tie up heavy burdens, hard to bear, and lay them on people's shoulders, but they themselves are not willing to move them with their finger" (Matthew 23:4). In contrast, Jesus said, "Come to me, all who labor and are heavy laden, and I will give you rest. Take my yoke upon you, and learn from me, for I am gentle and lowly in heart, and you will find rest for your souls. For my yoke is easy, and my burden is light" (Matthew 11:28–30).

If the Gentiles take on circumcision, it will be a sign that they are under the Mosaic law and they expect to be saved by following it (Galatians 5:1–6). Peter points out that even Jews can't perfectly follow the Law—how could Gentiles? Peter finishes by reminding the leaders and the Pharisees that Jews and Gentiles are saved only "through the grace of the Lord Jesus" (Acts 15:11).