Memorial of Saint Thomas Aquinas, priest and doctor of the Church
And the scribes who were come down from Jerusalem, said: He hath Beelzebub, and by the prince of devils he casteth out devils. And after he had called them together, he said to them in parables: How can Satan cast out Satan? And if a kingdom be divided against itself, that kingdom cannot stand. And if a house be divided against itself, that house cannot stand. And if Satan be risen up against himself, he is divided, and cannot stand, but hath an end. No man can enter into the house of a strong man and rob him of his goods, unless he first bind the strong man, and then shall he plunder his house. Amen I say to you, that all sins shall be forgiven unto the sons of men, and the blasphemies wherewith they shall blaspheme: But he that shall blaspheme against the Holy Ghost, shall never have forgiveness, but shall be guilty of an everlasting sin. Because they said: He hath an unclean spirit.
Mark 3:22-30 (Douay-Rheims Bible)
Dear Father they said Jesus had an unclean spirit, and since you are part of Jesus and the Holy Spirit is part of both of you, then what Jesus said is true. The Holy Spirit is a very big part of you and Jesus and it's sad when anyone blasphemes against the Holy Spirit. Jesus took offense and I don't blame him either. Don't we defend our families when anyone says anything bad or against them. Sometimes we might overlook a grievance about a brother or a sister, but when it is aimed at a loving parent, then that's altogether different. They are not just role models, but the very essence of family. The Holy Spirit is the essence of the Holy Family and woe to anyone who seeks to blaspheme against him. Jesus said it best.