Question: "What does it mean that a house divided cannot stand?"
Answer: There are three accounts in the Gospels in which Jesus states that a kingdom divided against itself is laid waste or a house divided cannot stand (Luke 11:17; Mark 3:25; Matthew 12:25). All three instances of this statement are spoken in response to the Pharisees’ accusation that Jesus was casting out demons by the power of Satan—a blasphemy that Jesus said would not be forgiven them.
Jesus’ argument to the Pharisees was logical: a kingdom that is at cross-purposes with itself will fall. Any household riven by infighting will tear itself apart. Jesus was obviously casting demons out of people. If Jesus was in league with Satan, or if Satan was somehow working through Jesus, it is unlikely that exorcisms would be a priority, because why would Satan cast himself out? Satan has more practical wisdom than to allow his demonic underlings to group themselves into warring factions.
By saying that a house divided cannot stand, Jesus is illustrating the fact that success relies on congruency. This is something we see in daily life all the time. Whether it is a machine, a sports team, a government party, or one’s own mind, things have to work together if anything is to be accomplished. The Bible says that a double-minded man is unstable in all his ways (James 1:8), and Paul appeals to the churches that there be no divisions among the believers (1 Corinthians 1:10). In fact, churches should be unified in their purpose and judgment, avoiding people who cause divisions and create obstacles contrary to sound doctrine (Romans 16:17). Christians are not to quarrel but to be unified around a common understanding of truth. “How good and pleasant it is when God’s people live together in unity!” (Psalm 133:1).
God commands unity among believers because, once conflict enters the midst of any assembly or entity, productivity and usefulness inevitably grind to a halt and the whole organization is weakened and becomes vulnerable to attack. As Jesus said, “Any kingdom divided against itself will be ruined, and a house divided against itself will fall.”
A fruit of the Spirit is peace (Galatians 5:22). Christians are, as followers of the Prince of Peace, peaceful people (Matthew 5:9). We are called to live in harmony with one another (Romans 12:16) and, as far as it depends on us, to be at peace with everyone (Hebrews 12:14). Jesus Christ is building His church (Matthew 16:18). His “house” will stand; “his kingdom will not be destroyed, / his dominion will never end” (Daniel 6:26).