All unrighteousness is sin. (1 John 5:17)
The sin not leading to death is ignorance, hence forgiveness, hence repentance, hence righteous belief. ( faith.)
You seem to not speak about faith very often, moreso on sin and transgression, in 1 John.
Here is good reading for all, for righteous faith...
Romans 4:5 But to him that worketh not, but believeth on him that justifieth the ungodly, his
faith is counted for
righteousness.
Romans 4:13 For the promise, that he should be the heir of the world, was not to Abraham, or to his seed, through the law, but through the
righteousness of
faith.
Romans 9:30 What shall we say then? That the Gentiles, which followed not after
righteousness, have attained to
righteousness, even the
righteousness which is of
faith.
Romans 10:6 But the righteousness which is of faith speaketh on this wise, Say not in thine heart, Who shall ascend into heaven? (that is, to bring Christ down from above
7 Or, Who shall descend into the deep? (that is, to bring up Christ again from the dead.)
8 But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach;
9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
Galatians 5:5 For we through the Spirit wait for the hope of
righteousness by
faith.
Philippians 3:9 And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
10 That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;
11 If by any means I might attain unto the resurrection of the dead.
1 Timothy 6:11 But thou, O man of God, flee these things; and follow after
righteousness, godliness,
faith, love, patience, meekness.
2 Timothy 2:22 Flee also youthful lusts: but follow
righteousness,
faith, charity, peace, with them that call on the Lord out of a pure heart.
Hebrews 11:4 By
faith Abel offered unto God a more excellent sacrifice than Cain, by which he obtained witness that he was
righteous, God testifying of his gifts: and by it he being dead yet speaketh.
Hebrews 12:24 And to Jesus the mediator of the new covenant, and to the
blood of
sprinkling, that speaketh better things than that of
Abel.
Hebrews 11:7 By
faith Noah, being warned of God of things not seen as yet, moved with fear, prepared an ark to the saving of his house; by the which he condemned the world, and became heir of the
righteousness which is by
faith.
2 Peter 1:1 Simon Peter, a servant and an apostle of Jesus Christ, to them that have obtained like precious
faith with us through the
righteousness of God and our Saviour Jesus Christ: