The atheist who feels it his duty to rage against religious faith and religious institutions. This is the Richard Dawkins, Madalyn O'Hair, ACLU variety and although I suspect they are the smallest in number, they are the noisy minority that give the rest of us a bad name.
The atheist who openly admits his atheism, is willing to defend it in public, yet who respects other's faith and acknowledges a role for faith in public life. This is where I am and it's where I've been for the last half a century.
The atheist who feels it necessary to conceal his unbelief for family, social, or professional reasons. The woman to whom I've been happily married for the last thirty years is one of these....she sat in church for two decades and mouthed the phrases which she did not believe. I suspect that many like her are to be found in every church, synagogue, and maybe even a mosque or two. They are in my opinion the largest group of atheists by far.
They could come in 100 flavors, but they all have in common the fact that they insist on thinking and living on the primitive, horizonal plane.
All and any atheists must defend their lack of belief. It’s not an option, there is no respect for religion within any atheists. There are no sweet fuzzy atheists, only the self-centered know-it-all, have to see it to believe it, me, me, me. I have a bit of respect for someone who calls themselves “agnostic”, none for the other. Not personal, but there it is.