What does 1 Corinthians 5:4 mean?

Paul has passed judgment on a man in the Corinthian church. The man was sleeping with his father's wife, a form of sexual immorality even the pagan culture of the day did not tolerate. In his position as apostle, founder of their church, and spiritual father, Paul has commanded them to remove the man from among them.

Now Paul tells them to do so when they meet. In doing so, he elevates the idea of "going to church" beyond a mere meeting of like-minded people to a gathering together in the name of the Lord Jesus. Physical gathering of believers is not merely an option, or a suggestion: it's a command (Hebrews 10:25).

As Paul did in the previous verse, he declares he will be present in spirit at this meeting, as well. Again, it is unclear in exactly what sense Paul means this. He will be present in the form of his letter to them, declaring this man guilty and commanding that he be removed. Paul has also said that he will be present spiritually, either in the sense that all of those who are in Christ are together or beyond that in some special supernatural sense by the power of the Lord Jesus. At minimum, Paul intends them to understand his judgment in this issue to be binding.

Paul is also claiming that it is with the power of the Lord Jesus that he will carry out the sentence for this man described in the following verse.