I remember having a discussion with one of them (or a similar proselitist) for 1 hour. She just kept saying "The trees are proof that god exists and the bible is his sacred word which was spoken down directly by him to his prophets" you know that typical statement. She never left making circular statements. In the end i told her "Look, what about I don't impose my views on you and you don't impose yours on me? Have a nice day" and went away.
My mother once told to one "Look, I don't come to your home at 9 am telling you to join my religion, do I? Since you're now bothering me with your presence why don't you come, shut up and listen to me so that I convince you that my views, and not yours, are right?"