Jesus ascends a mountain and summons twelve special disciples. He gives them all the authority to preach and exorcize demons. Sweet.
The narrator lists the names of the twelve elite disciples.
Some of the more noteworthy are the nicknames Jesus gives to Simon, who will be called Peter (which in Greek means "Rock"), and to James and John, who will be called "Sons of Thunder." No, Jesus is not starting a band. We don't think.
Also a part of this group is Judas, who will later rat him out. Ooh, that's juicy. When? How?
Jesus enters a house, and a huge crowd gathers. They can't even find time for a lunch-break.
His "family" (1:21) arrives on the scene to get him under control. The KJV translates this word as "friends." Either translation is possible, but don't decide for yourself until you check out 3:31-32.
Basically, they're saying Jesus is nuts.
That means Jesus's own family agrees with scribes from Jerusalem that something just isn't right about Jesus. But the scribes are saying Jesus is possessed by one of the most powerful of the otherworldly demons named Beelzebub. How else are you going to explain his ability to order the other demons around?
Jesus defends himself against the scribes. By the scribes' logic, the demons are having a civil war or something. If they are, then their kingdom will collapse, which is a good thing for everyone.
Also, if you want to steal someone's stuff, then you have to tie up the strong man who will otherwise stop you. True enough, but the point is…?
Jesus concludes with some very threatening trash talk. God is more or less forgiving of people, but never ever (ever) will God forgive disrespect toward the Holy Spirit. The scribes who say Jesus is possessed by an "unclean spirit" rather than the Holy Spirit are in some real big trouble.
The narrator resumes the story he started in 3:20-21. Jesus's mother and siblings, who are outside, are trying to talk to him.
The crowd reports this to Jesus, who asks, "Who are my mother and my brothers?" (NRSV). Maybe his family's right. Jesus does sounds a little nuts here (remember 3:21).
Wait, though, Jesus has a point. He looks at the people sitting around him and calls them his mother and brothers.
Huh? How could Peter be his mother? Well, Jesus explains that whoever does God's will is his mother and sibling. There he goes, re-defining family in a way that has nothing to do with ties of blood.