What does Galatians 2:5 mean?

Paul understood that he was on the front lines of a battle for the truth of what it really means to be saved. What does it mean to be a Christian and included in the family of God? What do you have to "do" to make it in?

Paul, who received the truth from Christ Himself, insisted that nothing was required of a person to be saved, because Jesus had already paid the full price for our salvation when he died for our sins on the cross. A group in the church known as the Judaizers could not accept this. They had accepted the idea of Christianity, but they wanted to blend it with the law of Moses. According to them, you must follow Christ, but you must also be circumcised and follow the Law to be saved.

Paul called these men "false brothers" and spies with the aim of stealing away the freedom Christ had purchased with His death. They weren't Christians, because they did not trust Christ's death to be enough to pay for their sins. Paul now says that he refused to budge an inch on this all-important point at a meeting in Jerusalem with the most influential leaders of the Christian movement. He saw it as his job to preserve the truth of the gospel.

This is a point on which the Bible is excruciatingly clear: adding even the slightest hint of "works" to the gospel, requiring any kind of ritual or act on our part, is to replace the truth with a lie.