If you were reading a story about a grown man that discovers that his real biological father was a Catholic Priest that became a bishop, would you be more interested if the bishop were still alive or the guy doesn't find out until the bishop is dead?
Of course that does add a lot of conflict, which is good. The bishop would not want to be exposed and punished by the church. And he would want to be a Cardinal.
He would have been following his son but not letting anyone know he is his son. They may already know each other (I haven't decided yet) and interacted but the kid just doesn't know he is the guy's biological son. So he could know his son as a person but just not letting the son know the true relationship. I guess it is more what is more tense: a guy finding out the priest he knew from childhood and had respect for, maybe even considered him to be his mentor, but not finding out he's really your "father" until after his death, or confronting an old man with ambition while he is alive.
Still fleshing this out because there could be good stuff between mother and son. Was the relationship she had with the priest consensual or part of the recent sex abuse scandals. If it is abuse and the son had always respected the priest and then finds out his mother is just now coming out with her accusations it could be really explosive if he doesn't believe her, then finds out through DNA or something that she was telling the truth.
I am with Reece here. If his father is alive, and if your MC is catholic as well, just by knowing that detail it must confront from his believes. He must ask himself many questions, and who knows? His/Her journey as a believer may change? Maybe he will find the church a circus? Hypocrites? Deceivers? I will suggest you do some research on stories similar to what you want to explore.
Well if you want similar that would be "The Thornbirds" by Colleen McCullough. I always hated that the kid never knew in that one. I want it to be different though, that is why I think the priest should have been a pedophile that abused the mother. But then if the kid knows the priest as a mentor I would have to have a good reason why she would let him near the priest while he was growing up unless I can figure out a way that she didn't know.
Neither. "Bishop is missing. We don't know is he dead or alive. We don't know is he voluntarily missing or not. We found this diary but it does not tell us much. This is not first time he is missing, but this might be more serious than previous case was. And we can't tell you anything about that case."