You are trying to pick a fight it seems to her....you should drop that subject
STOP pushing your beliefs on her. That's a very quick way to end a friendship.
When you "bug" someone, they are certainly going to get upset about it after a while. I don't blame her. Try being nice and forget about your belief differences and be her friend! Then maybe she will return your messages.
Do you pick on her to get her attention? Do you have a crush on her? Ask her out already instead of playing games. If you don't stop she will look for a less annoying friend.
It sounds like youre the problem. You even admit that you enjoy winding them up. Is it really a surprise they stopped talking to you? If you really want to fix it, apologise and stop deliberately annoying them.
American essayist Ralph Waldo Emerson once said: “The only way to have a friend is to be one.” A true friend is quick to overlook minor failings. To illustrate: Some do not like eating raspberries because of their little seeds. Those who enjoy this fruit, however, do not notice the seeds. True friends are loved for their fine qualities; their minor faults are overlooked. When you are talking with her, show personal interest in her feelings. Take the lead in displaying honor to her, by respecting her beliefs even if you don't agree. Then she will want to be friends with you. On the other hand, if you monopolize every conversation, or constantly put yourself in the limelight, you will have a hard time finding someone who is ready to listen or who cares about your feelings and needs.
Too many things seperating us.
All you need is Love.