Everyone who is an atheist is an atheist plus many other things. Humanism is a very comprehensive world view, covering many specific ethical issues. Atheism happens to be one component of the more comprehensive Humanistic world view. In the same sense, atheism pervades a variety of comprehensive world views, including Humanism.
Nobody is just an atheist.
Every atheist is an atheist among other things. It is this ome minor component, atheism, which is the object of much bigotry and discrimination in America and elsewhere. Thus, we advocate for the rights and dignity of atheists of all stripes, atheists who suffer for the atheistic elements of their more comprehensive world view. Again, we advocate for the dignity and rights of those who suffer for their atheism. Excerpts not exceeding 500 words are allowed provided the proper copyright notice is affixed.