Jesus said this because the people were saying that he had an evil spirit in him.
Some teachers of the Law of Moses came from Jerusalem and said, “This man is under the power of Beelzebul, the ruler of demons! He is even forcing out demons with the help of Beelzebul.”
But if you speak against the Holy Spirit, you can never be forgiven. That sin will be held against you for ever.
Jesus' mother and brothers came and stood outside. Then they sent someone with a message for him to come out to them.
Many of them said, “He has a demon in him! He is mad! Why listen to him?”