I have decided to become an Atheist

[Raven]

An atheist is someone who has looked at the available evidence and come to the conclusion that the evidence does not support the existence of a deity.

Uh, you're ascribing a lot of nonsense there to what atheism actually is. Sorry to be pedantic. Atheism has nothing to do with evidence, or conclusions, or indeed looking. That has to do with the reasons someone may be an atheist. All atheism has to do with is whether or not someone believes in a god/gods. Their reasons can be wildly different, and certainly not every atheist is an atheist because they have done what you say.

OK, Napoleon. Pedantic or not, what you say is true enough. So let me rephrase - I myself took a look at the available evidence, (that is, available to me) and over a long period of time came to the conclusion that no deity exists. I am quite willing to change my mind should I ever find a compelling reason to do so. Other people may arrive at the same conclusion for whatever reason, perhaps no particular reason at all to another persons way of thinking. All would still be atheists.

But if you are angry at god, then you are not an atheist. You have to believe in the existence of someone before you can be angry at them. I'm angry at a lot of things, but I cannot be angry at someone I don't believe in the existence of.