I am an Atheist.
Those four little words can enrage communities, sadden people, and destroy families. By turning your back on someone's god, they feel you have turned your back on them. This makes them feel angry, disappointed, and many will even pity you.
However, that's not to say you should force yourself to believe in their religion. That's the worst course of action for both sides. False belief is a lot worse than either belief or dis-belief. If you truly don't believe in any god or religion, then it is better to get it out in the open as soon as possible. The longer you wait, the harder it will be.
For me, it was simple. I was spoiled as a child in the realm of religion. Even though my parents had strong feelings about religion, in varying directions, they never forced their beliefs onto me, allowing my own thoughts to guide me. I tried out various beliefs, never attaching myself to any of them, and eventually settled on an Agnostic viewpoint for a long time. Finally, full Atheism was the only viable option I could see. They were fine with it, and encouraged me the whole way. So, I can't pretend to know how hard it is to express disbelief in heavily religious families. I do know, though, that any painful secret will continue to build as you get older, and eventually wall itself in until you can't tell anyone, forcing you to live a double life.
Once you're out in the open about your “beliefs” you can focus on more important aspects of your life, like LIVING IT! Many hours are spent every week catering to a religion, not least of all being religious gatherings. Once those are out of the way, you can use the time for things you enjoy or working toward a goal. One thing that will be a problem, though, is that you will need to put a little bit of time into your defenses. Not so much physical defenses (unless you live in one of those third world areas) as religious ones. You may not want a fight, but almost every heavily religious person you meet, and say you are an Atheist to, is going to attack you in one form or another. Most of these attacks can be deflected using common sense, but some can be jarring, especially if you do not have an answer for them. So, I recommend brushing up now, even if you haven't told anyone yet, because those attacks will get rather vicious.
For those on the fence, or curious about the Atheist position, I encourage you to stay with this blog. I will attempt to explain our side, without resisting anyone, and show why we are growing in number. Every month I will answer a question directed at Atheists, in an attempt to help those who just don't understand us. Starting with this first, easily answered question:
“If there is no God and no afterlife, why do you even bother going through life?”
Simple, because there is nothing else. This is the only life we have, so we must live it as best we can, accomplishing what we can. Many would argue that there is no point since there is no reward after death, but I disagree. Generations of people may remember you for what you have accomplished, even if they don't know you by name. For example, Gary Gygax is the father of Role Playing Games by creating Dungeons and Dragons. Every RPG from that point on has been based (in whole or in part) on his design. Have you ever heard of him until now? Chances are you haven't, yet I bet you or someone you know plays RPGs all the time, and probably also has never heard of him.
Many years from now, no one will remember us, but they will remember what we've done, even if all you did was create the one that did something great.