I think it is interesting to be with someone who has different views, opinions and beliefs. However, if they tried to convert me to their religion, get me to visit their place of worship etc, then I wouldn't.
I just don't get why someone believing in an entity that you do not is a deal breaker for you. I probably have a different interpretation of quantum of mechanics to you. I don´t get why anybody would feel the need to believe in something that as you also said "doesn´t exist".
However, it is not necessary to be any or all of those things to sincerely believe in the existence of a deity.
And even if someone did have "faith" as their only reason for belief in their deity of choice, well, it would be a huge turn off since it is overtly irrational, but still if they were a benevolent person and didn't mind my atheist ass I could look past it.
For the sake of them she feels forced to have a religious ceremony or have her child baptized if this case ever occurs. But what about situations where you are confronted with religion?