Religion spreads by a process known as viral memetic infection, which is reinforced by psychological conditioning from the various religions themselves until the belief (which itself is based on a process of circular logic) becomes "hard wired" into the brain, at which point the brain accepts certain irrationalities at a fundamental, hard wired level. This is the reason why people of deep faith can't "think" their way out of it, it literally becomes impossible to question certain fundamental beliefs.
Asking a person of deep faith to accept the concept that there are no gods and their religion is nothing more than a control system is like asking you or I to accept the notion that we don't have to breathe or our hearts don't need to beat - it's such a fundamentally accepted concept that it is beyond questioning. This is also the reason why you cannot have a completely rational conversation with a religious person about their religion, there are certain concepts they simply can't accept. This is due to it become hard-wired neurologically through repetitious thinking and the psychological reinforcement that religions employ.
It is also the reason why religious people deal better with stress - the actual biological make-up of the religious brain differs in it's wiring, and one of those differences is a severe reduction in activity in the anterior cingulate cortex, which is a part of the brain dealing with error recognition and critical thinking (explained in this article: http://www.sciencedaily.com/releases/2009/03/090304160400.htm).
For more information on Viral Memetic Infection see Diane Benscoter's excellent Ted talk
Plainly, because of the above, we cannot hope to "convert back" or open the eyes of those already caught in deep faith, their neurological programming prevents it. They are simply incapable of having a totally rational discussion on the subject, even though they will be convinced they are, and nothing short of a traumatic event in thier lives which causes them to question their thinking as a whole down to a very fundamental level can start that process. All we can hope to do is teach these facts to the young to educate them as to how these things work and thus prevent them of falling into the trap of organised religion before they succumb to it.
How cults rewire the brain-