I agree with your message, except I don't agree with your conclusion on all this. I believe deliverance ministries go against what the bible teaches, therefore they are not being doers of the Word, but are going against the Word.
And I have seen the testimonies of people that were deliverance ministers themselves and also of the people that were part of these ministries testifying of how it didn't work. And I've seen it first hand myself. I had a group of friends years ago that were all into the deliverance ministry type stuff. They talked about demons continually. They are still plagued today with the same issues and more it seems. It's just like the healing ministry stuff with the healers themselves sick and unable to be healed and then all the people they don't heal left bewildered because it's all built up to be so great and this is where the answers are, but it's a lie.
We are in a battle no doubt, with the flesh, the devil, the demons, the world, other christians with bad doctrine. :) We are told to resist all that is not of God and we do that by believing the truths of the scriptures, mainly the gospel. We are not told to go get a bunch of stuff cast out of us and that it will come out in our phlegm, puke, coughs, or whatever else (like the guy from the radio program said :)). No, resist all of it, that's what we are told to do!