1 John 5:17

“All unrighteousness is sin, &c.] All unrighteousness against God or man is a sin against the law of God, and the wrath of God is revealed against it, and it is deserving of death; yet all unrighteousness is not unto death, as the sins of David, which were unrighteousness both to God and man, and yet they were put away, and he died not; Peter sinned very foully, and did great injustice to his dear Lord, and yet his sin was not unto death; he had repentance unto life given him, and a fresh application of pardoning grace: and there is a sin not unto death; this is added for the relief of weak believers, who hearing of a sin unto death, not to be prayed for, might fear that theirs were of that…”

“"Every unrighteousness (even that of believers, compare Jo1 1:9; Jo1 3:4. Every coming short of right) is sin"; (but) not every sin is the sin unto death. and there is a sin not unto death--in the case of which, therefore, believers may intercede. Death and life stand in correlative opposition (Jo1 5:11-13). The sin unto death must be one tending "towards" (so the Greek), and so resulting in, death. ALFORD makes it to be an appreciable ACT of sin, namely, the denying Jesus to be the Christ, the Son of God (in contrast to confess this truth, Jo1 5:1, Jo1 5:5), Jo1 2:19, Jo1 2:22; Jo1 4:2-3; Jo1 5:10. Such wilful deniers of Christ are not to be received into one's house, or wished "God speed."…”

“All unrighteousness is sin ... - This seems to be thrown in to guard what he had just said, and there is “one” great and enormous sin, a sin which could not be forgiven. But he says also that there are many other forms and degrees of sin, sin for which prayer may be made. Everything, he says, which is unrighteous - ἀδικία adikia - everything which does not conform to the holy law of God, and which is not right in the view of that law, is to be regarded as sin; but we are not to suppose that all sin of that kind is of such a character that it cannot possibly be forgiven. There are many who commit sin who we may hope will be recovered, and for them it is proper to pray. Deeply affected as we…”

“All deviation from perfect holiness is sin; but all sin is not unpardonable. 1 John 5:18”

“5:17 not every sin leads to death: Those sins that do not involve ultimate apostasy can end in repentance and restoration (see Jas 5:20).”

“all: Jo1 3:4; Deu 5:32, Deu 12:32 and: Jo1 5:16; Isa 1:18; Eze 18:26-32; Rom 5:20, Rom 5:21; Jam 1:15, Jam 4:7-10 1 John 5:18”