Sin » The unpardonable
"If any one shall speak a word against the Son of man it shall be forgiven him; but he who is blasphemes against the Holy Spirit shall not be forgiven.
but he who blasphemes against the Holy Spirit is never forgiven. Nay, he is in the grasp of an eternal sin."
If any one sees his brother committing a sin that is not deadly, he shall ask, and God will give him life, for any one who is not committing a deadly sin. There is a deadly sin; concerning that I do not say that he should pray. All unrighteousness is sin; and there is sin that is not deadly.
"Therefore I tell you that every sin and blasphemy shall be forgiven men; but the blasphemy against the Holy Spirit shall not be forgiven.