Can a Christian living in open sin still be saved?
Yes, Scripture indicates a believer living in open sin can still be saved, though not without consequence. Paul writes that such a one may be turned over to Satan for the destruction of the flesh, yet the spirit may be saved in the day of the Lord Jesus.
Les explains that the man in Corinth was a believer, or Paul would not address him as such. The church was to deliver him to Satan for the destruction of the flesh, not the soul or spirit. Satan can only go as far as God permits, as with Job. If this couple would not clean up their act and come away from open sin, they could be turned over to Satan to take their physical lives, lest they keep bringing reproach to the name of Christ. But this does not mean spiritual annihilation; the spirit may be saved in the day of the Lord Jesus. Les notes it is hard for many to comprehend that people living in this kind of sinful condition are still saved, but that is what the book says, though they will not get away with it.
To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.