I reject the existence of an all-powerful and all-knowing god if it means abandoning human free will. But does rejecting the god of supernatural theism require the rejection of the reality of god in its entirety? No. But it does require a different understanding of the reality of god and the characteristics of omnipotence and omniscience.
A hallmark of most major religions is that God is omniscient, that he knows everything. He knows the future as well as the present and the past. This has spawned many an argument over the extent of free will.