Mark 3:20-35

Jesus returns home from a preaching tour and finds that His ministry has followed Him. People are boundary-less and in any ministry this is part of the work. There has been a shift on the part of many in ministry to make it a profession and less of a calling. Ministers sometimes hide behind staff and doors and secret means of contact. For Jesus, if He wasn't away with the Father then He was available. 

The prior testimony of demons may have been the inspiration for the accusation of the scribes. This is not an honest mistake because they were attempting to join with the demonic to undermine Jesus's ministry. Do not think that anything that demons did was a result of worship or adoration. Note also that the scribes came from Jerusalem. This was a 60-mile distance as the crow flies. The accusation was the merger of two forces that oppose Jesus, the demonic and religious elite. If opposition to Jesus to this point was scattered and individual, it has now become the official policy of the religious powers. 

Jesus proves the failure of their thinking by showing that a house divided will fall. We don't appreciate this because we do not understand the immensity of the liberation that Jesus brings. When Jesus cured the demon-possessed person it was no minor improvement. It was extreme and radical. The horrible, wretched life of the demon-possessed might change a little for the better as the demon toyed with the person and their loved ones.  But what we see when Jesus heals a person is a change so great and complete that they are virtually unrecognizable. 

Blasphemy of the Holy Spirit ought to bring holy fear to any heart and cause us to practice extreme care and reverence in all matters related to the things of God. In short, to reject the work of the Holy Spirit, in this case by attributing it to Satan, is unforgivable. Such an action hardens the heart and leads to a cycle of rejection of God making repentance impossible. 

Verse 31 and following is likely an explanation of verse 21. Jesus’ kin had a plan for His life and His agenda did not match theirs. To follow the will of the Father meant for Jesus, and for us, that the relationships formed in obedience and being a disciple is stronger and closer than even that of family.