Player Backstory-NPC: Should I adress this with the player first?

Situation:
The player's backstory involved his parents disappearing under mysterious circumstances. So far he managed to reunite with his father and is now looking for his mother who is very likely deceased. (which yes, she is.)
The player's plan is to find her and if dead, resurrect her.

Now here's the part where it gets tricky:
The world is a monotheistic Theocracy that is very comparable to Catholicism.
Necromancy magic is outlawed as it is considered heresy as it is considered to be antithetical to life. This includes resurrection magic. So the father being a simple, godfearing farmer will be against the ressurrection.

On the one hand this would present a very interesting roleplay situation and generelly interesting discussion to persuade the father that it's the right thing to do (or even respect the father's standpoint and leave her to rest in peace).
On the other hand I feel this is a very strong encroachment into a player's backstory NPC - though he never gave me more beyond a name, race, age and artwork, told me I can feel free to add my own ideas and is so far happy with how I portray the father.

Now.
Adressing this with the player seems for me like the most sensible thing. But I find it difficult to approach this.
I could either go the direct route in "Would you find it ok if your father as a god-fearing man would be hesitant about resurrecting his dead wife/your mother?" which would have the drawback of spoiling the entire surprise.
Or I could be roundabout and ask "Would you consider your father to be a religious man?" which I feel is a bit of a disingenuous trap question.
Other option would be to ask again if he gives me all the liberties concerning his backstory NPCs that are sensible to the game world's logic.
Or the last option is to simply not adress it at all and let the "bomb" drop without warning.

How would you approach that situation?