Most Christians don't have experience in casting out demons. I'm willing to bet that most Christians in the west have a hard time believing demon possession is a serious problem in our present world or that they have a part to play in casting out rebellious spirits. I'll be the first to say that I have always been skeptical of the power of demons and how much I am obligated to fight against them. Spiritual warfare talk often seems so... well, fictional. It seems like barbaric and pre-enlightenment superstition mumbo jumbo. I'm convinced this is an unhealthy view.
In his book Satan and the Problem of Evil
, Gregory A. Boyd brings forth statements from several post-apostolic Christians (church "fathers" from the first 3 centuries after Christ). Boyd aims to explain the early Christian belief that all angels (both obedient and fallen) are free will agents (like humans). As a result of this many angels have rebeled (following "Satan") and are now roaming Earth (again following "Satan.") Not only are Satan and these fallen angels inhabiting Earth but the early Christians give us reason to believe they are causing a lot of trouble that often gets blamed on God. To put blame on Boyd and avoid too much research I'll throw some snippets from the book your way.
Origen insists, "famine, blasting of the vine and fruit trees, pestilence among men and beasts: all these are the proper occupations of demons." So too demons are "the cause of plagues... barrenness... tempests... [and] similar calamities." Similarly, Tertullian argues that "diseases and other grievous calamities" are the result of demons whose "great business is the ruin of mankind."
In the footnotes Boyd writes, "Interestingly enough, Origen relates the power of demons in the natural world to the 'nourishment' they gain from 'the savor of burnt sacrifices, blood, and incense' offered to them in the context of pagan religions."
In a nutshell Boyd is claiming the early Christians believed that demons have free will, operate in the world humans live in, and cause trouble not only with humans but also the elements of the planet such as water, dirt, and so on. Mudslides, earthquakes, and more are attributed to the devious acts of rebellious angels in the eyes of Tertullian, Origen, Tatian, Justin (the Martyr), Athenagoras, and others. In other words, there is an evil will behind all evil that exists and that evil will is born of the agent it comes through and not the original Creator.
If this is all true, then it certainly makes the practice and need for casting out demons much greater and it also makes much more sense of the account that the Christians of the first few centuries would extinguish small sacrificial altars in the market places and worship centers of the pagans when they would come through. For me, it makes such action an act of war, service to the world and a practical way to live out an understanding of Ephesians 6:12 and 2Corinthians 4:4 as opposed to a public nuisance. What do you think? Does this sound biblically accurate to you? What is your understanding of the cause for natural disasters? Do you believe casting out demons should be more common?