Knowing Eternal Life, Confident Prayer, and Sin unto Death

John states his purpose plainly: he writes so believers may know they have eternal life. This closely parallels the Gospel of John’s purpose statement that its signs were written so readers may believe and have life in Jesus’ name. Assurance leads into confident prayer “according to his will.” The difficult phrase “a sin unto death” follows. John does not identify the sin with enough precision to justify dogmatic certainty, and interpreters have proposed several possibilities: persistent apostasy, a particularly grave sin, physical death under divine discipline, or a category related to the opponents’ rejection of Christ. A responsible reading should present the major options and clearly preserve the uncertainty. The secure point is that John distinguishes sins in the pastoral context of intercession while still affirming, “All unrighteousness is sin.”