Although unbelief makes people go to hell, it is more than a mind thing. Instead of happening all in the mind, we show unbelief with our actions. For example, in a parable Jesus describes actions that typify unbelief. He says, “Who then is that faithful and wise steward whom his master will make ruler over his household to give them their portion of food in due season” (Luke 12:42)? Jesus begins first by asking, Who is believing? Thus, he says, “that servant whom his master will find so doing when he comes” (Luke 12:43). Jesus shows that the believing servant will do something when his master returns.
Unbelief means disbelief or faithlessness. Specifically, it means disbelief in Jesus Christ. Jesus, answering his disciples who wondered why they couldn’t cast out a demon in a man, said, “Because of your unbelief, for assuredly, I say to you, if you have faith as a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move: and nothing will be impossible for you” (Matthew 17:20). Jesus emphasizes the extreme power of faith in contrast to unbelief. Furthermore, unbelief does not have to be matched by an extreme amount of faith to be overcome. Such a requirement of little faith shows 1) faith is way more powerful than unbelief and 2) God honors faith by empowering His followers.
Jesus says, “if I cast out demons by Beelzebub, by whom do your sons cast them out? Therefore, they will be your judges” (Luke 11:20 KJV). Jesus points out the hypocrisy of some people who witnessed Jesus casting out demons. Some people said that Jesus cast out demons by Beelzebub. Beelzebub (or Beelzeboul) was a name of Satan. This name translates as “the lord of the flies” or “fly-god.” This name emphasizes that Satan is over so-called “demonic flies” or demons. It was this authority over such demons that people claimed Jesus had. According to their view, only Satan could command demons since he had authority over demons. Thus people claimed that Jesus operated with the power of Satan.