I always hate it when some non-atheist tries to define and explain what atheism means. They say things like, "Atheism means that you know there is no god. You can't be that certain." Or they say "Atheism means you are against theism and/or you hate god and religious people. I'm' thinking of trying this response out:
Many people think the term atheist by itself conveys a lot of hostility and presupposes unjustified certainty. To help you understand why that is not correct, consider the similarities between the terms atheist and asexual. Both labels provide information about a person by identifying a lack of preference for something many other people find worthwhile. The term atheist does not imply certainty that god does not exists any more than the term asexual denies that sex exists. Also, you can identify with these labels, while not disparaging other people who might be monotheists, pantheists, polytheists, deists, heterosexuals, homosexuals, bi-sexuals, polysexual, omnisexuals or whatever.
There is nothing inherently contradictory about atheists or asexuals recognizing that many people get pleasure and meaning from practicing their favorite theisms and sexualities and wishing them nothing but the best on their favored path. So, I'd appreciate it if you would not assume that the label atheist automatically indicates that I have some sort of grudge or harbor ill feelings towards religious people. But please feel free to assume that it does imply that I would appreciate it if you did not push your junk in my face all the time. I'm just saying.