Now he was casting out a demon that was mute. When the demon had gone out, the mute man spoke, and the people marveled. But some of them said, “He casts out demons by Beelzebul, the prince of demons,” while others, to test him, kept seeking from him a sign from heaven. But he, knowing their thoughts, said to them, “Every kingdom divided against itself is laid waste, and a divided household falls. And if Satan also is divided against himself, how will his kingdom stand? For you say that I cast out demons by Beelzebul. And if I cast out demons by Beelzebul, by whom do your sons cast them out? Therefore they will be your judges. But if it is by the finger of God that I cast out demons, then the kingdom of God has come upon you. When a strong man, fully armed, guards his own palace, his goods are safe; but when one stronger than he attacks him and overcomes him, he takes away his armor in which he trusted and divides his spoil. Whoever is not with me is against me, and whoever does not gather with me scatters.
(Luke 11:14-23 ESV)