1 Corinthians 5
But whether it means that the offender had seduced his step-mother, or that the woman was divorced from his father, or that the father had died, leaving her a widow, is not clear.
To be expelled from the church accordingly is to be delivered over into that region where Satan holds sway. It is a very forcible expression for the loss of all Christian privileges.
One sees ‘the flesh’ as the lower part of man’s nature, and takes the passage to mean the destruction of the sinful lusts (so NIV, that the sinful nature may be destroyed; cf. Redpath, he ‘is to be given over to Satan until that principle of yieldedness to the flesh is ended’)
The other view is that ‘the flesh’ is to be understood as physical, the reference being to sickness and even death. The difficulty is in seeing how this could be effected by excommunication. But Paul speaks of physical consequences of spiritual failings (11:30)
Paul sees the punishment as remedial: though the flesh be destroyed it is so that his spirit may be saved. That this means saved in the fullest sense is made clear by the addition, on the day of the Lord. At the final day of judgment he expects to see the disciplined offender among the Lord’s people.
Christ is for believers what the passover was for the Jews.
Ancient Israel was commanded to remove all yeast before the sacrifice (Exod. 12:15; 13:7), and in Paul’s day a feature of passover observance was a solemn search for and destruction of all yeast before the feast began. This had to be done before the pascha, the kid or lamb, was offered in the temple. Paul points out that Christ, our Passover has already been sacrificed. It is time and more than time that all yeast (i.e. all evil) was put away.
The verb to associate with (synanamignysthai) is an expressive double compound, used outside this passage only once in the New Testament (2 Thess. 3:14; see note in TNTC). It means ‘to mix up yourself with’; Paul has forbidden them to have familiar intercourse with sexual offenders.
His point had been that they must not maintain intimate fellowship (the same picturesque word as in v. 9) with anyone who calls himself a brother, but denies his profession by the way he lives. He is not really a brother, but ‘a fornicator’ or the like.
Believers are to have no intimate intercourse with people who continue in such practices. Do not even eat will refer primarily to ordinary meals (cf. 2 John 10), not to Holy Communion, though that, too, would be forbidden.
But Paul’s main point, that the church must not tolerate the presence of evil in its midst, is clearly permanently relevant.