I want to be friendly towards girls on Facebook?

I just want to talk to girls on Facebook, but I end up getting ignored :\ I always wonder why but I have become so used to it that I am losing hope in ever having a friend or a girlfriend at that. I don't want to bug them anymore after they don't reply to my messages or comments and I will just ignore them for days and just "like" their status updates. Why do girls do that? (Ignore me) i am very friendly and I don't use profanity, nothing bad ever posted from my part on my Facebook, I am Christian so I usually post bible verses or prayers, I post other stuff of my personal interest but nothing profane or obscene. Maybe that's what girls like in guys is what I wonder, they like guys that post nasty and stupid junk on Facebook. I don't go out I just spend time working 8 hours 5 days a week, I have weekends free but just stay in or go out to run errands. I get lonely I have no friends, they all abandoned me. I just want to make a female friend through Facebook and see how it goes, I have social anxiety, very shy, but when you get to know me I am the most out going and fantastic person :D but no one knows about that since I have no one. What can I do? Is there something I am missing? Something wrong I am doing?