Spiritual Warfare: Supporting the concept of spiritual warfare

This site is basic, but the problem they face here is that a believer Can be demonized in a spiritual walfare. It shocked me, im serious. But later reading more it was a problem to see that we all face the same problems as being "demonized" where when we fall in temptations we are acting like one.
http://www.rapidnet.com/~jbeard/bdm/Psychology/warfare/demonp.htm



" Can a believer be demonized; i.e., possessed by a demon?
There is a movement within professing Evangelicalism today that says, "Yes." This movement is teaching that a high percentage of sin among Christians is caused by demons. Followers assent that a person can be a believer in Jesus Christ, experience fullness of salvation, and still be in bondage to Satan and demons.
The popularity of this movement can be seen in the seminars being held across the country and the best-selling books being published that promote this teaching. Nonetheless, this teaching of the "demonization of the believer" is contrary to Scripture and is in line with the world's view of everyone being a victim.
It is a denial of the sufficiency of the work of Christ and Scripture.
This teaching of the demonization of the believer has not come without a forerunner. Christian psychology has brought the world's idea of victimization to the Church. Psychology has taught us that everyone is a victim. When a person has problems in his life, he is often told it is the result of his past or how his parents treated him. The end result is that he does not take responsibility for his own actions. We see this today. People are suing cigarette makers because they have smoked for fifty years and are dying of lung cancer. Criminals claim that their dysfunctional families are the reason for their criminal acts. Everyone is blaming someone or something else for their problems.
Now there is a different twist. Now our deviant behavior is being blamed on Satan and demons. This is the flip-side of psychology. In both cases, there is something other than ourselves to blame for our sin. Both make the believer a victim who needs the steps and formulas of the "experts" in order to find true joy and victory.
Christian psychology's emphasis on experience and stories also parallels this teaching on the demonization of the believer. In Christian psychology, the source of authority is experience rather than Scripture. Now with the demonization of the believer movement, one finds the same "theology by story" emphasis. And in the process, the Biblical way of dealing with people's sin problem has been abandoned. "