There were two main objections, which my atheist opponents defended during the VT debate on the existence of God. One of the objections was from the problem of gratuitous evil, particularly natural evil, which I have already responded to here. The other objection raised during the debate was presented first after my opening statements. The argument was that because me and my debate partner were Christian theists the Christian God cannot exist because of the supposed atrocities in the Bible and other doctrines such as hell.
The argument began with the problem of predisposition. In other words, why you must approach your faith of choice with objectivity and skepticism and not confirmation bias. However, in response, in order to identify and affirm the discovery of a truth one must not exhaust all possibilities. Additionally, it works both ways. If the criterion is applied fairly how can one deny the proposition, in this case, God exists, without examining all possibilities? This criterion is untenable. Also, to suggest that one is a Christian because of environment or spatiotemporal location is to commit the genetic fallacy.