The emotional cost of breaking up will be infinitely smaller than what you will both bear, should you undergo this.
It's clear that you don't *really* fully believe in the religious doctrine (if you did, we wouldn't be having this conversation).
You will not be able to fake your dedication to this cult. It will wear you down
It will put a big cloud over your marriage. A cloud that only YOU can see, but can't talk about and resolve. You'll be miserable, or maybe insane from trying to convince yourself that you're happy, and it was all worth it.
She's not worth it. No one is.
I used to think I knew someone who was, but I was wrong. Now I realize that I couldn't have been right in that regard, because you (or I) can't live a life for someone else.
Don't do it, even if for her sake. If you pretend to believe (but really don't), she will feel deceived when you eventually give out.
Good on you for putting this out there. There are people in this crowd who know. Look at the overwhelming message you're getting...