We will be examining the interpretations and explanations that abound regarding 1 John 5:16-17. Every imaginable sin has likely been named through the years as the sin unto death. Usually, the foulest of sin is selected as that sin unto death. Which sin is the sin unto death? Is it murder, incest, rape, sodomy, child abuse or something like idolatry? Is it one of what is commonly called “The Seven Deadly Sins?” Is it the sin of non-productivity, hypocrisy, scoffing at the things of God, carnality, defilement of the body, sexual immorality, or ingratitude? Is it blasphemy against God in general, Jesus Christ or the Holy Ghost in particular? This study will endeavor to at least answer some of these questions.

source https://www.free-ebooks.net/religious/A-Sin-Unto-Death