The metaphysical naturalist (atheist) view is that "all that there is" is matter in all its motions, microscope to telescope. The necessary consequence of that line of thought is that the "mind is what the brain does" that "there is no ghost in the machine."
That means the mind is merely an epiphenomenon of the physical brain. An epiphenomenon is a secondary phenomenon which can cause nothing to happen!
The atheist's "reality" (a false, second reality actually) - unfolds according to physical laws and physical constants only. What is called a "choice" is an illusion, it can cause nothing to happen. It is like a circuit board, cellular automata, or a phenomenon emerging from self-organizing complexity. The universe, in the atheist view, is executing its program.
Moreover, atheism fails on causation per se.
If not for time, events would not occur. If not for space, things would not be.
Every cosmology has a beginning and they all rely on space/time for causation. Yet there is nothing in the void of the beginning - no space, no time, no energy, no matter, no physical laws, no physical constants, no thing and especially no physical causation. There must be an uncaused cause of causation itself, i.e. God.