She told me to leave

i have been in a relationship for 3 years. it started out sexual. i asked her to move in about 2 1/2 years ago. she has 3 girls that i try to be a father to. now she has been a christian for about 6 years. we have been going to church for about 4 months now and she told me to leave cause we are sexually immoral. i love her im sure she loves me. we have talked a little about marriage.

marry her or walk away