1/. Romans 3:20 “Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin.
2/. Romans 14:23 “And he that doubteth is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin.”
3/. James 4:17 “Therefore to him that knoweth to do good, and doeth it not, to him it is sin.”
The unforgiveable Sin? Only one recorded – Matthew 12:31. see also Hebrews chapter 10 and Galatians chapter 5. Ephesians 4:26.
1 John 2: 1″My little children, these things write I unto you, that ye sin not. [The perfect will of God] And if any man sin, we have an advocate with the Father, Jesus Christ the righteous.” [The acceptable will of God]. Also 1 John 1:5-10.