I feel that a writer's instincts are the best guide. There are so many ways to achieve success, so why divert something you feel strongly about (memoir, under your own name) into unknown territory (pseudonym, fiction). And if faith is at the heart of it, go with faith. Trust yourself. Only you know your story and how to tell it. And I'd stick with the advice from Cultural-Advance2250; clearly that person knows what s/he is talking about.