Read this passage and open each verse for the full verse feed and commentary tools.
28"Truly, I say to you, all sins will be forgiven the sons of men, and whatever blasphemies they utter; 29but whoever blasphemes against the Holy Spirit never has forgiveness, but is guilty of an eternal sin"-- 30for they had said, "He has an unclean spirit."
Mark 3:28-30 (RSV)