I normally deal with the door to door religious types by slamming the door on them. However, I had a room mate some time ago who simply loved talking with these people. He was a Political Science major and very well read on various religions. As soon as he found out one of the evangelists was a the door he would rush over and invite them in. He always started out very polite, sitting them in the living room and offering refreshments while saying polite things and admitting his sins. Gradually over the course of ten or fifteen minutes he would shift the course of the conversation to cover inadequacies of the relevant scripture and the contradictions of the evangelists explanations. After about twenty minutes he was in complete control of the conversation and would often end by denouncing the faith and yelling at the poor sods till they ran out the door in tears. It always made me feel a little guilty that I laughed so much.