We had talked briefly a few times prior to my approaching her.
So it wasn’t completely out of the blue. I feel like this part is pretty critical. You had established yourself in a positive way before making the ask. If your first-ever interaction with her had been asking her out on a date, I doubt it would have gone as well.
It’s been awhile since I’ve seen it, but IIRC, the film isn’t saying the Christian Jesus we all know about is immortal, but that this character in the film who is immortal (and a white dude, BTW) was assumed to be the son of God because people 2,000 years ago found out he was immortal and had no other explanation.
ETA: Looks like I remembered reasonably well. Here’s the scene in question: https://www.youtube.com/watch?v=6bXtdr5BI74