When Arwen says 'there is no ship that will bear me hence' I always take it as not that there is
literally no ship, but that she simply would not go there, that she wants to go where her husband has gone. And that underlines just how much this is all about simple love between a couple.
You could take many relationships, including the one between Aragorn and Arwen, where one partner believes one thing strongly, and the other something else, something opposite or nothing at all (not meaning they are a nihilist, that they may be an atheist). Yet for a lot of couples in order to be together one needs to convert or to at least go along with the rituals etc of the other partner. In Tolkien's case, he wanted Edith to convert to Catholicism and she did, though I understand she was never very happy about it - in an Anglican society of which she had been very much an active part it left her somewhat on the margins. But that is what Love does, it often causes partners to compromise. How many of us have seen white women who take the veil when they marry a Muslim man? That's a big step to take, especially bearing in mind the abuse some of these women endure just because of what they wear. But it is love which does this.
Now bearing that in mind, I don't think there is a conflict in Tolkien's work between belief and love - in fact in showing us the example of Aragorn and Arwen he shows us that Love can be stronger and can overcome lifelong held beliefs for good or bad. And Arwen does not simply go against a religion that she has been brought up with but against her very nature. You can only presume that it was love for her husband that made her take the choice to be mortal and to die, and part of that love must have been to believe what he told her - that they would meet again.
What does intrigue me is how it always seems to be the woman who compromises
