Atheists often offer believers to show them God, and then they promise to believe in Him. Let me offer you a way to detect God - He is found by the very fact of your existence. You are the immortal soul, created by God, and a material body. The fact that you have free will, is evidence of the creation of your by God. It is with this reality you they  trying to argue, calling himself an atheist.

The point is that atheist cannot be anything other than materialists. For the materialist only matter is real. The phenomenon of consciousness with a materialist position is due to some complex processes in the human brain matter. This means that all human actions are caused by the state of this matter, and not by his free will. From the standpoint of the materialist free will of man is only an illusion, and a person cannot be the cause of his actions. All decisions of the man and all actions, arising from them, are determined.
It is possible to discuss and even write books on the lack of free will, but I weakly imagine how you can implement it at the level of self-awareness - to live with a clear understanding, that you are not independent in yours decisions, unforgiving rock of materialistic determinism prevails above you, and your life scheduled to the smallest detail despite yourself.
Even the most ardent atheists behave as if they have a free will in their decisions. You may have noticed that atheists like to condemn believers for various sins? In terms of atheistic worldview it is quite ridiculous because believers determined to be believers. Here is no moral responsibility, because the cause of human actions are not their decisions taken in accordance with free will, but some material prerequisites, which, in theory, can be traced back to the Big Bang.
Therefore, if you are not willing to gladly accept the idea that you are just a complex biological mechanism, highly manipulative in its decisions and dependent on unknown materialistic laws of existence, and somehow accept such life, overcoming misleading of free will, then you are not an atheist, but a confused believer.