Josh McDowell, who has probably participated in more theological debates then anyone from the theist side, after many years came to the conclusion that "the reason nearly all atheists won't believe when presented with evidence is that the evidence is not the issue with them but instead some sin in their personal lives". No matter what the evidence is it will not be good enough or they categorically reject it to continue to cover up their own real personal sin issue. The more testy they are then the more the guilt is festering. Many feel that debate with these people is futile because you can never get to the real problem.
