i haven't read the others' posts yet, i'll go back and read them, but i have to say off the bat, that your SO is struggling with your christianity in the same way that others struggle with polyamory- that is, she has a fixed definition in her mind of what it means, and struggles to come to terms with the reality that religions mean different things to different people. i wonder if you wrote a few journal entries on what religion means to you, and how it complements your life, if she might get a better picture.
my sister is christian (i am not), but she is very mystic in her beliefs. my pagan friends were at first very worried about her, but after conversing with her, soon found out that their fears were unfounded. i think that sometimes the image of 'a christian person' is set in their minds and it takes a while to change that perception.
i would be hesitant to date a christian person, mostly because i don't want to date anyone who thinks i'm going to hell because i'm pagan. christians who don't believe in hell, or don't believe that unbelievers are going to hell... those kinds of christians i could date.
i also don't believe that anyone who asks you to give up your beliefs for them is someone worth pursuing. your SOs should accept and love you for who you are, and your beliefs strongly influence what kind of person you are.