My family is very religious, but i'm not sure any gods exist?

I've been brought up by Christian parents, who do the "pray at the table" thing, and they teach sunday school every sunday, and listen to sermons, and try to include "god" into their daily lives. But for the past, eh, year or so I have been having some serious doubts. I'm now to the point where I feel like I don't think it's right to tell people that they should have love and compion for one another but at the same time tell them it's okay to do things like hate gay people, or believe in god or else you will be killed by an "antichrist" when the time comes. And i don't think there's enough evidence to support that god exists anywhere. My problem is, I feel so out of place when I have to lie every sunday to my parents when I go to church and pray, when I'm sure no one is really listening. I don't know how to tell my family, and what this will do to them. I'm only fifteen. I'd really like some advice.