What does 2 Corinthians 13:7 mean?

Paul has issued an ominous warning to the Corinthians: when he arrives, none in unrepentant sin will be spared from discipline (2 Corinthians 13:2). He followed that by urging them to examine themselves to see if they were in the faith (2 Corinthians 13:5). This suggests they ought to scrutinize their own beliefs and conduct. That should show whether they were living according to their existing faith in Christ. Paul wants them to test themselves to see if Christ is in them.

If they find they do, in fact, believe in the true Christ—as Paul expects they will—it also means Paul has passed the test of being a true apostle of Christ. After all, how could the Corinthians come to true faith in Christ if the one who introduced them to Christ was a false apostle, as Paul's opponents claimed?

Another implication is that if the Corinthians continue in unrepentant sin, it will create an embarrassing situation. Paul will appear—to those outside—to have failed to introduce them to Christ. He quickly adds that his point is not that he's extremely worried about looking good to anyone. It's not the appearance of bringing them to true saving faith in Jesus that matters. In fact, Paul is more than willing for outward appearances to make him look like a failure, so long as the reality is that his work helps bring people to Christ.. What he wants above all is for them to do what is right and, in that way, give evidence that their faith in Christ is true.

Paul's deepest hope for the Corinthians is that Christ is truly in them. Their ability to repent of sin and to continue to follow Christ will be evidence of their faith. He is not saying that giving up sin is what will save them, however. Only faith in Christ can do that (Ephesians 2:8–9).