Hebrews 10:26,27
For if we sin willfully after that we have received the knowledge of the truth, there remains no more sacrifice for sins,
Torrey's Topical Textbook—AKJV

1 John 5:16
If any man see his brother sin a sin which is not to death, he shall ask, and he shall give him life for them that sin not to death. There is a sin to death: I do not say that he shall pray for it.
Torrey's Topical Textbook—AKJV