Mark 3:20-30 NRSV
and the crowd came together again, so that they could not even eat. When his family heard it, they went out to restrain him, for people were saying, “He has gone out of his mind.” And the scribes who came down from Jerusalem said, “He has Beelzebul, and by the ruler of the demons he casts out demons.” And he called them to him, and spoke to them in parables, “How can Satan cast out Satan? If a kingdom is divided against itself, that kingdom cannot stand. And if a house is divided against itself, that house will not be able to stand. And if Satan has risen up against himself and is divided, he cannot stand, but his end has come. But no one can enter a strong man's house and plunder his property without first tying up the strong man; then indeed the house can be plundered.
“Truly I tell you, people will be forgiven for their sins and whatever blasphemies they utter; but whoever blasphemes against the Holy Spirit can never have forgiveness, but is guilty of an eternal sin”— for they had said, “He has an unclean spirit.”
NRSV: New Revised Standard Version