Mark has a curious way of telling two stories at once that we tend to separate: Jesus' response to the teachers who accused him of throwing out demons by the power of Satan, and Jesus' mother and brothers trying to get face-time with him. We separate them because Matthew puts them back to back but doesn't tell them as a single story, and also Luke does the same and obscures the connection further by putting the actual arrival of Jesus' family elsewhere in his book. But as Mark tells the story, Jesus' family comes to take Jesus away forcibly, believing him insane; then Jesus responds to the scribes' accusation that he is possessed by Beelzebul; then the family arrives and Jesus asserts that his real mother and siblings are those who do what God wants. (This suggests another reason that we probably separate the two stories: Mark's version portrays Jesus' family in an uncomfortably bad light.)
A few things stick out to me here.
The world is so unused to seeing evil defeated that they think that there must be evil behind it when it happens. And they are so unused to seeing people do what God wants that even seriously religious people think that people who do must be crazy. This shows how screwed up is the world we're living in and how badly we go against the grain when we even get started really displaying the reign of God.
And yet, Jesus never stopped going against the grain. I don't know how I would persevere if people accused me of being pure evil or if my close family believed that I need to be involuntarily committed to a psychiatric unit. But Jesus did. He never stopped going against the grain because he was remaking the grain. That's what the reign of God is all about.
Of those who opposed, misunderstood, and even slandered him that day, some remained in it stubbornly but others turned around. The scribes, or at least most of them, stayed stuck in their opposition to Jesus. But his mother and brothers became part of the backbone of the church. Never count out those who think you're crazy because of your obsession for God's reign, especially those who, like Mary, have once heard the good news and humbly received it.