To understand the point of a passage it’s usually helpful to ask questions like who? what? why? how?
Starting with “who?”…
This is the apostle Paul (who we’ve seen was called by God to preach the gospel of Christ to the Gentiles), writing to churches in Galatia (who had heard the gospel of Christ from Paul but were now turning to a different gospel), and he’s writing about a dispute he had with Peter.
So what can we learn from the who in this passage? Well sometimes we might think we’re too well taught to ever fall for the kind of error that the Galatians went along with, but I think if someone like Peter wasn’t immune from acting in a way that conflicts with the truth of the gospel, we probably need to keep an eye on ourselves. Unless we think we’re better Christians than the apostle Peter, let’s not assume this is just an issue for other churches out there to be concerned about.
Next question: What did Peter do wrong?
v12 he withdrew from eating with the Gentiles, and v14 tells us that the problem with this was that it was “not in step with the truth of the gospel”.
v13 tells us Peter acted hypocritically. So apparently he was teaching the true gospel, but his actions said something different. Officially he taught the true gospel, but he was actually sending out mixed messages so that people would’ve got the impression from him that faith in Christ wasn’t actually enough to justify them and they needed some works of the law too.
So if the apostle Peter officially taught the true gospel but then, when it came to practice, was actually sending out a different message, we should probably be discerning about the preachers we listen to. Sure, a man may hold to all the right confessions, tick all the right doctrinal boxes, but does he send me away praising Christ for what he did for me, or do I go away feeling like I need to do some work to make sure I’m truly justified?
Why did Peter act hypocritically?
v12 says it was because he feared the circumcision party. In other words, he wanted to keep them on his side; he didn’t want to offend them and risk having them shun him, he wanted to preserve unity with them. So I think the lesson from this why question is: if the price of unity with other people who call themselves Christians involves us acting in a way that’s out of step with the truth of the gospel, then that price is not worth paying.
We might fear the consequences of offending other Christians, but we should fear God more, and trust that he’s got a plan. If people are offended by our acting in accordance with the gospel, it’s not going to take God by surprise; somehow he will make it work for his glory.