New Defender's Study Bible Notes
5:20 save a soul. This verse can properly be considered an incentive for soul-winning in general. In context, however, it seems to refer primarily to the particular case being discussed—that of a professing Christian whose sin has resulted in divine chastisement in the form of sickness. As long as he persists in his sin, refusing to confess and forsake it, he is in danger of eventually being consigned to physical death (note I Corinthians 5:5; 11:30; I Timothy 1:20). This is probably the “sin unto death” mentioned in I John 5:16. There is thus a great need for concerned Christian friends to try diligently to “turn him back” (the meaning of “convert”) from the dangerous course he is traveling. It is even more urgent if his professed faith in Christ was not genuine in the first place. He then needs to be saved not only from physical death but also from eternal, spiritual death.