I am an atheist not because I do not believe in anything, but because religions push beliefs that I cannot accept.
Some of the things I do believe:
People are fundamentally decent and good. - We may not all agree with each other, but people do things because they believe its appropriate and the right thing. People who are "anti-social" aren't all so just because they were born haters, or because they're 'dark', 'sinful,' or 'tainted.' They are people who need help, who need human sympathy. Because too often, we fail to understand that not everyone lived the same kind of life as ourselves. Not everyone feels the same things, or holds the same beliefs. Not everyone has had as much love and acceptance. Yes, there are some who act truly senseless harm on others, but its not because they're evil, but because they're ill.
We make our own luck. - Our fates aren't determined by chance or a roll of the die, an invisible hand or a mythical diety, but foremost by our own efforts. Sometimes it seems that the whole world is hellbent against us. Of course, the world isn't very fair by any means, but unless we persevere, we cannot see what lies over the horizon. Yes, sometimes bad things happen to good people for no fault of their own, but if we put our minds to it, any person can accomplish great things. But it's not going to happen if we lie back and do not try, instead blaming fate, or luck, or God, or whatever.
Life should be cherished. - There is much more to this than creating more lives. That's meaningless, and only harms so much life already on this planet. The true essence of cherishing life is ensuring that life that already exists in the world needs to be taken care of. What joy is life if it is spent in squalor, poverty, or sickness? I would rather ensure the happy lives of the thousands who live now, than have them create a thousand more. Furthermore, cherishing life extends not only to people, but to animals, plants, and all the living things with whom we share our planetary home.
The universe is a mysterious place. However, if we're willing to stretch the limits of our thoughts and imaginations rather than remain afraid of what we do not know, we can discover truly amazing things. We will better understand the world around us, and we can make happier, fuller lives for all.
The central tenet of a "moral" life is not religious doctrine, but a much more fundamental idea: caring for your fellow person. Everything else follows from that basic principle.
And as a sum of several of these: humanity does not need mysticism, religion, dieties, or spiritual guidance to flourish, for people to be 'good', to achieve true happiness, or for salvation. In so many ways, these ideas separate ourselves the world around us, and from nature. That does not mean they serve no purpose. They can help us or make our lives more satisfying. But we must not cling too much to religion or any other arbitrary beliefs. Doing so makes us blind, it clouds the truth. It makes us forget that yes, every one of 'us' is a human being, just like you and I, with the same essential hopes and desires.
~k