There are combinations of personal traits that will have you on edge with people of the cloth. That is; being truthful to others and your self, respecting all individuals, and being inquisitive and willing to learn. In learning, one will undoubtfully clash ones childish believes upon the mountains of knowledge, and if one is truthful to one self, those early misconceptions will be cast away.
For most of us there is no courage involved in breaking down those early misconception. We have no barriers of guilt or pain, or are not so bound to our parents that we do not dare part from their believes. But for some those barriers exist.
For those whose faith will do no harm, I'd tread lightly but firmly in any discussion. Respecting them means not letting them live out their lives in a lie, but one must also means to acknowledge their need for consolation, even if that on which they support themselves is not real. As W. I. Thomas famously said "If men define situations as real, they are real in their consequences". And I try out of the respect for their wishes and feelings to not hurt them unnecessarily.
At one time I didn't have that luxury, as one of my friends wanted to become a priest. In discussions with her she shelled off layer after layer of belief - but at that centre there was a core of fear, immovable and untouchable. The immorality of being a priest is something I presume you have thought a lot about, so I will not dwell. But in the end I think her disillusionment drove her to another field of work.
So thank you for your arguments, your viewpoints and for not underestimating your readers. And I think I'll continue to step lightly, but firmly.