Paul asks: “Did you suffer in vain?”
So there must be a kind of suffering that’s not in vain. In 2 Corinthians 12 Paul says “For the sake of Christ, then, I am content with weaknesses, insults, hardships, persecutions, and calamities. For when I am weak, then I am strong.” Paul’s suffering for the sake of Christ led to him experiencing the power of Christ resting upon him and the sufficiency of God’s grace. And in Matt 5:10-12 Jesus tells those who are persecuted on his account, or for righteousness’ sake, should rejoice, because it’s an indicator that theirs is the kingdom of heaven, where they’ll receive a great reward.
Why might the Galatians’ suffering have been in vain? If they weren’t actually justified. With this series of questions (v2-v7) Paul connects the question “are you now being perfected by the flesh?” with how we’re counted righteous and whether we’re “blessed along with Abraham” (v9) or “under a curse” (v10). So if the Galatians were, or if we are, confused about how we’re to finish the Christian life, Paul reckons that calls into question whether we’ve understood the gospel at all.
I think we’re probably all agreed that we need the Holy Spirit to work in us to keep us going and keep us growing in the Christian life. How do we receive the Holy Spirit? The Bible talks about people receiving the Spirit when they’re converted (Acts 10:44-48). None of us would claim we were converted and received the Holy Spirit as a result of our works of the law. But Paul says “supplies the Spirit” – he’s speaking in the present tense – so the way the Spirit is supplied to us hasn’t changed. It wasn’t faith at the time of conversion and from then on we have to work to stay in the Spirit’s good books. He who supplies the Spirit to us still does so by our hearing with faith.
People talk about grieving the Spirit, and it’s right to be wary of that, Ephesians 4:30 tells us not to grieve the Holy Spirit, but I can hardly think of a more certain way to grieve the Spirit than to try to earn his favour by works of the law rather than hearing his word with faith.