Hemant Mehta of the Friendly Atheist just released a video explaining why he feels obliged to promote atheism. I thought it was a good topic to discuss, so following his lead I will offer my own reasons of why I am an advocate for atheism.
Atheism is actually more than just the non-belief in deities. Don't get me wrong, the definition of atheism is certainly a straight forward concept, but what we might highlight as cultural atheism, including but not limited to New Atheism, the atheist thinkers who came out of the Golden Age of Freethough, such as the Great Agnostic Robert G. Ingersoll, the atheist thinkers who came out of various enlightenments, whether it is Paul Thiry d'Holbach or David Hume, are all representative of a secular tradition that upholds atheism as, perhaps, something more than just the mere lack of belief in God or gods.
Cultural atheism, like cultural Christianity, is merely a byproduct of living in a secular culture and society which adopts a secular worldview. There's nothing controversial about it. But at the same time, I have found that secular ideals often require things like good critical thinking, skepticism, and reasoning skills in order to remain truly secular. The moment age-old superstition creeps in you lose the secular world view and it gets supplanted by religious myths and fancies.
This requires secularism to maintain a kind of equilibrium with the various cultures it co-exists alongside, and this equilibrium, as far as I can tell, is largely dependent on two factors: naturalism (which atheism is a consequence of) and being open minded and flexible, i.e. being able to change one's mind about things--something quite anemic to religious beliefs.
Because I value things like truth, not multiplying assumptions unnecessarily, of being intellectually honest, it seems that all this and more can be encompassed within cultural atheism. That is to say, a majority of the things I value can be contained in this form of atheism.
It's much harder to value these things and be religious, at least not without a certain amount of cognitive dissonance, I'd imagine.
As such, atheism allows one to maintain a clear mind, because there is less cognitive dissonance. As such, it allows one to focus their critical thinking skills on things that matter, with a clarity that I lacked when I was a believer.
I like to advance atheism because atheism has no doctrines or creeds to advance itself upon, unlike the theocratic policies of many world religions. That makes it doubly interesting to me, because those who adopt atheism will have a wide array of political beliefs and worldviews, and it becomes the burden of the atheist to figure out which is the best, or at least, most beneficial one.
Similarly, atheism is pretty wide open because it makes minimal assumptions. So anything else you may believe in addition to atheism must stand on its own merits, unlike religion which uses its own assumptions to buttress itself up all the time.
If you choose to become an atheist, there is no laziness about simply having beliefs (as with religion), since it is your burden to find valid reasons for holding those beliefs, and atheism surely isn't going to make that easy for you.
But I wouldn't have it any other way.
Atheism is for thinking people, because it gives rooms for the free exchange of ideas, without any interference. It lets you learn more about the world while not telling you how you ought to think or believe.
It's quite novel in that regard.
Atheism is compatible with naturalism, democracy, science, and secularism whereas religion has a great deal amount of friction with all of these things. As such, to be religious forces you into a position of defense anytime any of these things are brought up as a topic of discussion, but with atheism there is nothing to defend (quite literally).
Atheists, I have found, tend to be more rational minded than believers. This doesn't mean there aren't rational believers, because I know some extremely smart theists and deists, but what I have noticed is that many atheists begin with one set of belief propositions and, having given them a certain amount of thought, rationalize their way out of these rigid belief systems to atheism. Because of this, many atheists (not all, of course--but many) are quite rational minded.
I know many deists who prefer to befriend atheists rather than their religious theist counterparts, because atheists are less judgmental of other beliefs, because for the atheist, if there is a true belief out there when it comes to God--we'd like to know it!
After all, atheists have nothing to lose.
Also, atheists are highly curious.
Ideas, beliefs, worldviews... all these and more pique our curiosity, so we're willing to sit down an talk about these subjects with practically anyone!
Atheists are social. At least some of them.
Atheists take care of themselves and live life to the fullest, because according to their worldview, it's the only life they have.
This makes atheists heaps of fun, because they have so many interests which they want to engage in to make the best of their lives!
Atheists care. Atheists are sometimes anti-theists, because we can see and identify the dangerous elements of religion which negatively impact people, culture, and society. Atheists want the world to be a better place, not a worse place, so we will argue against those things which we perceive to be an imminent threat.
Atheists are highly moral, in part because many atheists are also humanists. But also because we realize this being the only life we have, we don't want to spend the only life we have suffering and we don't think anyone else should either.
It is often said that atheists have no purpose or reason to live. This is only a half truth, because in all truth we all can find a purpose or a reason to live. It's like Sylvester Stallone said in the fourth Rambo movie, "Die for something, or live for nothing." Which is another way of saying you have to live and die for something otherwise you've lived for nothing.
So atheists aren't without purpose to life. Our purpose for living is whatever we make it, and because we don't believe in an afterlife we must make our purpose a good one so that this one, precious life will have meaning.
If you believe in an afterlife, then there is less of an impetus to attach any meaning to your life or find any real purpose--you are free to float in limbo hoping fate will give you a meaningful life. But atheists are realistic--we don't feel comfortable hanging all our hopes on a pipe dream, on fate, or on God. Not when we have the power to make our lives have meaning here and now.
Atheists want to help others because the here and now matters to us. We want children to have good scientific educations and we don't want religion to interfere with the education of our children. Lots of times this sentiment comes from atheists who were raised up religious, or who had religious educations, and see how truly inferior a religious education is to a secular one. This isn't to say all religious educations are bad ones, but the ones which limit knowledge to only what that religion will accept can never truly be about the unabashed learning one can enjoy minus those religious restrictions.
I could go and ad nauseam of why I find atheism attractive and worth advocating, but needless to say, I'm not going to force my atheism down your throat.
Although I find it worth talking about, I am not going to dictate that you should become an atheist. Unlike many religions, there simply no reason for an atheist to expect you to think and believe exactly like they do.
All this and more makes atheism appealing to me personally, but I think some of these reasons may make atheism a little more attractive to you as well.