Because born again Christians cannot be demonized (which is another word for dominated or possessed by demons), the casting out of demons from Christians is not Biblical. Colossians 1:13 proves this because it says that born again Christians are rescued from the dominion of darkness.
I can understand why one of this thread has issued the warning about "many will come in the name of Jesus..."etc., because we see many in the Pentecostal and Charismatic movement exercising deliverance ministries for Christians and boasting that they are casting demons out of them. If during an exorcism session a Christian exhibits what seems like a demon being coughed out, it would more likely be as the result of suggestion, that the person is brainwashed into thinking that this is what happens when a demon is cast out of him.
If a Christian is the temple of the Holy Spirit, he cannot have a demon at the same time. The passage that Jesus talks about where a demon has been cast out and wanders around and returns to find the "house" has been cleaned out and is empty and re-enters may be true if the person remains unconverted and the Holy Spirit is not in him. But if the demon returns and finds the person filled with the Holy Spirit, it cannot re-enter the person because the "house" is no longer empty.
Furthermore, there is nothing in the New Testament that shows that Christians can be demon possessed, and there are no instances where demons were cast out of Christian believers. Therefore any deliverance ministry for Christians is based on a lie.