How do I deal with my Christian parents?

Okay so in the past 2 years I've gone from moderate baptist christian, to liberal episcopalian, now I'm an agnostic. Without getting into too much, my dad knows I'm agnostic and he treats me like I'm the antichrist or something. He makes me go to church and he sings gospel songs and mentions Christianity like he's trying to make a point. He makes it seems like I claimed to stop being a Christian because I didn't want to follow "the rules" or whatever. Anyways on Sunday we went to church and when we were there I just sad down all pissed and had my arms folded and everything and I walked out and just sat outside. THen they came out and we went home and we didn't talk after that. Then I was home alone and my dad called me from work asking how was I or whatever then he bust out, do me a favor. I'm like okay, he told me to read the book of matthew and me and him and his fiance are gonna have a talk about it tommorow. I read part of it, and it's just pissing me off. I can't stand this, I want them off my back. Why can't we just agree to disagree. Someone help please. And also if anyone knows about the book of matthew can someone tell me why he might have chose it. I think I know why, other opinions would be nice.