Why I am a reluctant 'strong atheist':
Through empirical evidence we can demonstrate that there is no discernable point at which something becomes conscious, although nearly everyone would claim otherwise. Consciousness comprises the brain; perhaps not the entire thing.
We cannot find an instance of the brain defying laws of physics, so some would argue that our minds operate according to the laws of physics. Maybe there is another kind of physics we do not yet understand - but this is hardly a strong hypothesis in support of the existence of an identity beyond physics. Even random events could be recorded and deemed "physical". Asserting that there is another kind of physics in which there are evolving energies underlying our existence is... presumptuous.
We could conceive of an interface; an interface of significance, for the reason that behind the interface lies an entity limited significantly more directly by itself then by elements opposite it's side of the interface - but that is irrelevant, for there is already an interface between our bodies and the world beyond. My causation, in a colloquial sense, comes more directly from myself than the external world, assuming I exist in that sense and I am not just in a dream where my objective observation is subjective nothingness.
Each moment is defined by the content of my memory and thoughts. The passage of time is an idea expressed somehow in my brain, not something that is inherently sensed. My idea of "self" is an idea expressed by my brain, my mind.
It is not incorrect to say that I am always dying and being reborn as a new person. Although I can feel my existence as a sequence of time, my actions are determined by current state, which was determined by other states including my interaction with the "physical" world. When I die, my experience will no longer be defined by my memory and my thoughts. My experience simply won't exist, although I might choose to hope for such an unwarranted idea.
The last grasp to the idea of "God" by would-be Christians and other misinformed people is analogous to the idea that we posses "consciousness" or "souls" beyond our "physical" selves. In this case, "God" is the "soul" and we blame everything on him while supposing we blame our "free" selves. The idea of "free will" stems from the mysterious conception of a "soul", which is irrelevant if we deem such to be "natural".