23 Jesus called them over and responded with an illustration. "How can Satan cast out Satan?" he asked. 24 "A kingdom divided by civil war will collapse. 25 Similarly, a family splintered by feuding will fall apart. 26 And if Satan is divided and fights against himself, how can he stand? He would never survive. 27 Let me illustrate this further. Who is powerful enough to enter the house of a strong man like Satan and plunder his goods? Only someone even stronger-someone who could tie him up and then plunder his house.
Matthew Henry's Commentary on Mark 3:23-27
Commentary on Mark 3:22-30
(Read Mark 3:22-30)
It was plain that the doctrine of Christ had a direct tendency to break the devil's power; and it was as plain, that casting of him out of the bodies of people, confirmed that doctrine; therefore Satan could not support such a design. Christ gave an awful warning against speaking such dangerous words. It is true the gospel promises, because Christ has purchased, forgiveness for the greatest sins and sinners; but by this sin, they would oppose the gifts of the Holy Ghost after Christ's ascension. Such is the enmity of the heart, that unconverted men pretend believers are doing Satan's work, when sinners are brought to repentance and newness of life.