Matthew 12:24
22 Then they brought to him a demon-possessed man who was blind and mute. Jesus healed him so that he could speak and see. 23 All the crowds were amazed and said, “Could this one be the Son of David?” 24 But when the Pharisees heard this they said, “He does not cast out demons except by the power of Beelzebul, the ruler of demons!” 25 Now when Jesus realized what they were thinking, he said to them, “Every kingdom divided against itself is destroyed, and no town or house divided against itself will stand. 26 So if Satan casts out Satan, he is divided against himself. How then will his kingdom stand? 27 And if I cast out demons by Beelzebul, by whom do your sons cast them out? For this reason they will be your judges.
Testament of Solomon 21
26 Next, I called again to have Beelzeboul, the prince of demons, stand before me. I seated him on a raised seat of honor and asked him, 'Why are you alone, the prince of demons?' He replied, 'Because I alone remained of the angels of heaven that came down. I was the first angel in the first heaven, known as Beelzeboul. And now I command all those who are bound in Tartarus. But I also have a child who haunts the Red Sea; whenever he has the opportunity, he comes up to me, being subject to me, and he informs me of what he has done, and I support him.'
Notes and References
"... It is against this background of Jewish thought that the teaching and exorcisms of Jesus and the first Christians is best understood. Daimonion is used frequently in the synoptic Gospels, but only occasionally elsewhere. Mark clearly regards it as a translation equivalent for 'unclean spirit' (Mark 6:7,13, 7:25f), and Luke seems deliberately to avoid the word 'demon' in describing the exorcisms of the early church (Acts 5:16, 8:7, 16:16, 19:11-16, compare 17:18). The idea of demons or unclean spirits as the spirits of the dead is nowhere to be found. Demons are simply servants of Satan, particular manifestations of the evil in the world that is hostile to God (see particularly Revelation 16:13-14). We may note also that the idea of opposing armies of angels is taken up by New Testament writers, most clearly outlined in Revelation 12:7-9 (compare Matthew 25:41). Against this broader background several points can be made by way of clarification. a) We should not assume that these concepts of demons and demon-possession were simplistically naive. For example, there was no particular conceptualization of a demon, as having say an animal or human-like form. On the contrary, the unclean spirits were invisible-hence the need of some physical sign to prove the exorcism (Testament of Solomon 7, 10, 13, 47, 51, 54, etc.) ..."
Dunn, James D. G. Demon-Possession and Exorcism in The New Testament (pp. 210-225) Churchman: A Quarterly Journal of Anglican Theology, 1980