Free Will and the Impossibility of the Christian God

It may be impossible to prove the non-existence of gods or monotheism, but it is possible to prove the non-existence of gods that are defined with contradictory properties. For example, it is a logical impossibility for an omniscient being to create beings with free will. Here is an example of a logical disproof of the Christian God.

(1) If a being has free will, then no one can know how it will choose to act.
(2) An omniscient being knows how everyone will choose to act.
(3) God is omniscient. (by definition)
(4) God cannot create beings with free will. (by 1, 2, and 3)
(5) God has created beings with free will. (by most versions of Christian doctrine)
(6) Therefore, God does not exist. (by 4 and 5)

There are several ways around this argument. One is to abandon the notion of free will, but that calls into question God's judgment that people have disobeyed his will or willfully committed sins. The other is to claim that God somehow does not know how people will behave, but that negates his omniscience. Many Christians, in my experience, simply try to deny (1), but that makes a mockery of the concept of "free will". It is reminiscent of "Hobson's Choice", the story of the legendary stable owner who allowed his customers to choose any horse in the stable as long as it was the one standing nearest to the door. The choice was between that horse and no horse at all.

It is my opinion that this logical argument is a fairly ironclad argument against belief in a very popular conception of the Christian God--one that is both omniscient and capable of creating beings with free will. However, like many philosophical arguments, it does not address the real motivation that people have for belief in a god--the desire to survive indefinitely and control one's destiny. We did not invent gods just to explain the nature of reality, although most believers use gods to explain the mysteries of nature. We really invented them in order to give us leverage against nature. Supernaturalism is essentially that--the ability to trump our natural circumstances.