Alright so here's my situation:
My family is fairly religious. (Goes to church on Sunday, prays before bed and every meal; that kind of religious.) I've been an altar boy and I am a lector pretty much because they want me to and there is really no way I can say no without raising suspicion that I'm not really feeling the whole Catholicism thing. I'm a sophomore in highschool and I kinda want to just get through with my own life without constantly thinking about salvation and eternal damnation. On a grand scale,I also feel that everything can be questioned so the idea that the Bible in Catholicism is infallible and so is the pope does not sit well with me. I accept that there could be some fact, but I also accept that the fact that proving everything is an irrefutable truth. Really sorry if this offends anyone (and I know it will offend someone despite my efforts to be civil).
Anyway, getting back on track I don't know what to do or how to tell my family that I'm not as religious as them without them thinking I've been possessed by the devil or have some mental illness. Under certain circumstances, I 'd be ok with talking it out with them but religion is a touchy subject at best and once someone believes in something wholeheartedly it's rather difficult to get them to see your side.

As an Atheist myself, No I don't hate, bash, or belittle other religions/religious people, I just was in the same boat. What I did was just not worry what others thought and went with how I felt until I find somthing to belive in. and for me right now, it's myself, my brothers in arms, and the US Air Force. Belive in what your are feeling and don't let anyone tell you you're wrong, to each their own, and to hell with forced thoughts.

I'd just keep it to myself. I'm probably not an atheist, but I'm not exactly super religious at this point either. My family generally believes but are fairly liberal - but they'd still flip the fuck out if I was to tell them I was an atheist.

I mean, unless it's past the point at which it's a minor inconvenience, I just don't think it's worth the trouble.

I'm also "Catholic" but not really. I go to Catholic church, but that's only because my family probably wouldn't go to any other type of church. The Catholic church is corrupt and I don't like the fact that anything the Pope says becomes sacred. It's to the point where my mom is even annoyed with him, because in a sense Catholics seem to worship him, so I get what you mean when you say it bothers you when his word is deemed infallible. In most religions that are a branch of Christianity however, isn't the Bible always infallible? There's even a verse in there that says something like, "Nothing in this book is a lie." So I feel like it would be understandable in that context. The problem with the Catholic church; however, is that they leave you no room to interpret it for yourself and that's what bothers me. I would never openly say it, but I'm not really Catholic anymore. I just believe in God.

Your family might get bothered a bit if you said you were an atheist, but I mean at some point they have to realize you make your own decisions, right? You shouldn't bring it up until they do. Just go to church, I mean even if you don't really believe in it, that's not to say you can't learn anything at church. My history teacher mad a very good point once. Most religions are based on morals, so even if you don't necessarily follow it, you can still learn things from it.

My dad is an atheist so I mean from what he's tole me about religion is just to look at it logically. If you have done that (it seems you have) then you can choose whether you want to be an atheist or continue practicing your religion with your own set of beliefs or you could also just not really care.

As an Atheist, I have learned to respect religion. What it can do, how it is used, when it used... I respect each and every denomination, I'd even Scientology (but very barely).

It's okay to question. It's good that you are (questioning)... it leads you to greater path. But remember to find something to hold on to, an idea or a notion that things happen and the universe controls that. Whether it be by divine intervention, or by law's of nature and attraction, sometimes our lives and the lives of others are not entirely in our hands.

But I digress...

If you can find that thing to hold onto, you will remain grounded on that path to understanding life in your own way. You don't want to end up lost because you didn't believe in anything, or that you didn't fully find what your personal definition for being Atheist is.

History and Science keep me grounded, as I did become very lost last year and believed in nothing and felt like life was just was it was and people died, and that was it.

Atheism is a tough road to follow, because it is a whole other set of religions in its own. Scientist pray to Quantum Theories, Histories and Anthropologists pray to the past, and Humanists pray to the human spirit.

But once you've found your meaning and your rock in Atheism... you are so much stronger than you'd ever think you'd be. Because the biggest thing you believe in is yourself.

Atheists and other religions are generally way more flexible and respectful towards other beliefs. Catholic on the other hand, from what I can see at least, seems to be really rigid. Which means that you're gonna have a really hard time backing out of it, depending on your environment. It's definitely not something that should be forced on someone, though.
So if you do decide to become an atheist, just quietly fade away instead of declaring it out loud. That would give you less harm.

Special thanks you to all of you for replying! Based on what everyone suggested I came up with a plan for myself.I really enjoyed seeing all your takes on the situation too.