There are two kinds of atheism: strong (positive) atheism and weak (negative) atheism. The difference between these two is basically that a weak atheist doesn't believe in God, while a strong atheist believes in no God.
Weak atheism is essentially the same as agnosticism
]. It states that since we have no proof of a God, we cannot know for sure that one exists. Strong atheism states that since we live in a scientific world where the existence of things is determined solely by their observability, we cannot assume anything unobservable to exist. God isn’t observable, therefore he doesn’t exist (cf. Occam’s Razor). This doesn't mean that an atheist wouldn't WANT to believe in God, it merely means that he has no REASON to believe in it/him.
Strong atheists often question the special treatment weak atheists – and theists – give to religion. If they believe that the tooth fairy or Santa Claus do not exist, why are they willing to give God a benefit of the doubt?
Strong atheism is often equated with religion since it takes a strong stance on the issue. This is, however, fallacious. Religion is not based on rationality, and strong atheists value rationality over fantasy. Therefore atheism is not parallel with religion.
I do not follow atheism. I merely concur with it.