What happens to a believer who refuses to repent of a sinful lifestyle?
A believer who refuses to repent of a sinful lifestyle may commit a sin unto death, and God can take his physical life. God removes such a one lest he keep bringing reproach to His name. This is in God's hands, and no one is permitted to pray for the erring believer's death.
Les teaches from 1 John that there is a sin unto death. He explains that while some sins do not cause God to take a believer out of physical life, others do. When a believer refuses to come away from a sinful lifestyle, despite being dealt with, God may suddenly take them home—through a heart attack or car accident—lest they keep bringing reproach to His name. Les emphasizes that no believer or church body ever has the right to pray for the death of an erring believer; that is in God's hands. He also references Galatians 6:1, that spiritual believers should restore such a one in meekness, remembering we are all human and prone to fall.