Well, I'm on a genetic fallacy kick today. Watch Richard Dawkins commit the GF in this video. The GF is taught in university logic classes as an irrational, nonlogical way of thinking. See, e.g., my MCCC Logic text (Vaughn,
The Power of Critical Thinking: Effective Reasoning about Ordinary and Extraordinary Claims, 4th edition, pp. 169-170. Further note that Vaughn is an atheist. But atheist and theists can agree on principles of logic. The origin of a belief serves as an irrelevant premise in regard to the truth or falsity of the belief.).
Philosophers William Lane Craig and J.P. Moreland explain.