Is it common for your boyfriend to keep trying to force his religion on you?

Yeah, it's not going to work unless you can either accept his religion or if he accepts you don't feel the same. From a Christian perspective, it's tough being religious around people who you care about who are not, it feels like you have the cure for all the pain life throws and it makes you automatically want to share that, which I know is beyond annoying if you're atheist.