Deliverance from Evil Spirits

On the mission field, sooner or later you will encounter evil coming from the spiritual realm. It's a good idea to have an idea of where you stand before you, for example, have to stand before a Muslim shaman doing a trance ritual, as I encountered two years ago.

Here's some salient points from my class on Spiritual Warfare

• The word 'demon-possession' is not an accurate translation of the original text. A better one may be demonized, or simply 'to have a demon'. The demons may not always completely possess, as in control, a person, but they may have influence. As seen in the NT encounters of Jesus with demonized people, sometimes they may seem fine but then may occasionally exhibit strange behaviors as the demon ramps up bothering them.
• A Christian can not be fully inhabited by a demon as our spirit is now the Lord's. However, in the same way that you can sin after becoming a Christian, you can also yield ground (say via sin) to allow demonic influence even after becoming a Christian. Sometimes this gets to the point where they are doing things they would not normally do or acting very strangely.
• Demonic influence can come from sin, curses, family spiritual inheritance (like children being dedicated to other spirits), trauma done to you (as in the case of abuse victims), and dealing with the occult. When dealing with occult spirits it is good to fast and pray to prepare yourself first.
• Casting out demons is actually a part of healing the person. So it should be in the overall scope of discipleship etc.
• When casting demons out, you don't have to shout, they are not deaf. Also do not get angry, remember you are battling a spiritual power, not the person. There is no need to be dramatic and you can also just tell them to be silent and leave quietly so they don't make a scene.
• There is no magic formula to casting them out, but saying something like this generally works. "In the name of Jesus, get out of here and do not return. This person belongs to Jesus and you have no control here. We cut off any ties and any influence from Satan."