IMHO, you'll know if they are deeply religious way before the 4th date! If they are truly 'deeply religious', they probably won't be dating you unless they were trying to 'save' you. It could lead to a very interesting conversation! Sometimes other philosophies and ideas are interesting to discuss, depends on how much it affects your beliefs or ideas.

Woah! That sort of thing would be discussed BEFORE a first date. I don't have time to waste on numpties.

Don't judge/ don't argue it just creates distance/ respect her even whel she disagrees with you/ take an interest in her stuff, new as it might be to you/ let the love come through, don't get in the way. (BTW I have been doing research on UFO's for 50 some years and it's still just pieces in a jug-saw pussle)

Sorry I just can't handle that kind of stupid, fourth date/last date.

The simple answer is "stop dating them". This has happened to me, although I found out on the first date. There wasn't second I wrote a post about it earlier in the week, take a look if you want a chuckle.

On a more serious note, it is best to nip such things in the bud early on, otherwise you could get stuck in a relationship with someone who has conflicting views of some major fundamental topics. Speaking from experience, this does not end well.

First, I give them the benefit by acting like they were joking. If they persist, I’ll chime in. People very rarely change an opinion on the spot, but at least this exchange will show how we resolve conflict.

I'm open to other people's experiences so it'd be interesting.

I just can't see it panning out is all. it's like trying to live with a vegan when you eat meat. it's not going to last.

I find out before first date-lengthy phone conversation.

I’m not very subtle I would probably debate them and blow the date not that I would care at that point.

I’d just leave.

I must say I would be too tempted to debate them and challenge there views as it seems everybody wants to think they have justified true beliefs. For those who just have a hunch or intuition and jump to conclusions I would entertain and debate but ultimately It would probs put me off.

I'm generally an avoid conflict sort of person--so as long they're phrasing what they're saying as "I believe..." I'll indulge them a bit. If they start making statement like "This is true because..." then I'd have to speak up. I couldn't nod along and I wouldn't feel comfortable continuing to pursue a relationship with someone if I had to hide my view points.