You may not fit the standard of beauty (handsomeness) that many girls are taught through media to desire. Another possibility (and not saying it is you) is that the girls you are near may percieve you as too needy or too insecure or too passive for them to rely on to be protective.
Remember, Meek does not mean milquetoast and wimpy. Meekness is about having the power to act and yet being submissive. It is about self control. Do not confuse that with being effiminenatly passive. A powerful man of God is confident, not afraid and weak and (not trying to insult you) but whiny.
You are very young. I will let you in on something: Christian or not, women and therefore girls... ALL women and girls, are genetically programmmed to seek out men of the highest possible position of respect, financial capacity to provide for their offspring and an ability and desire to physically protect their offspring.
As a male and a man you must demonstrate these things to a woman in order to be appealing to her. Even a woman who has the "social mobility" to only ever be marreid to a "janitor" will still want the best provider of a janitor that she can be proud of. Your beleifs as a Christian are only PART of who you are as a man. You need to start workign on other aspects of who you are if you want a woman to be proud to be with you and eager to "show off" her man. Being a good Christian man does not negate the fundamental biology of being a human man.
I suggest hitting the gym, getting out and playing sports and generally meeting new people. Build some hobbies. I mean really do what you love, learn to be an expert in something, work on presenting information about that topic. Gain the respect of other MEN and you will gain the eye of WOMEN. That is how it works... that is God's plan... why? becasue a woman will never ever submit to a man she does not respect, and no woman will respect a man who is viewed as pathetic and unworthy of respect by other men.
You are completely capable of changing this around. Be yourself, celebrate who you are by honing the wonderful talents that God gave you (whatever they are)!
There is a man named Brian Tracy. He is small, thin man and has a very geeky voice (by my standards). Yet he is one of the top motivational speakers in the world... and a successfully married with four kids Christian man. He also has a smokin hot wife and is well-respected in his field. He has a talent for speaking and presentation, a talent given to him by God, that he multiplied and utilized well. He is a success. You can be too.
But you need to identify your talents, strengthen your body, build your confidence, and become not just a "nice Christian boy" but rather a powerful man of God worth respecting in whatever it is you do best. Surround yourself with likeminded men, men who want to encourage you and uplift you. Stop "hanging on" around girls who view you as a "pal." You are probably just annoying them and they find you clingy. Why? Becaseu that is exactly how most owmen view guys who hand around with girls that they refuse to go out with. They see you as feminized and "safe", not as masculine, a MAN. break the mold brother.
Christ did not seek out wimpy guys who were trailing after women in some desperate hope of being noticed. He picked MEN real men who were out doing hard work that they were talented at and successful at: fishermen, tax collectors, etc. remember, pigs wallow, human beings should not.
God Bless!