In many of the arguments about God and mind-body dualism there is the underlying notion of agency, or of an agent - an entity that has some autonomous control of its actions, some intent (i.e intentionality). If we can challenge the notion of agency then we can take a different view of the universe.
Dualists have an appreciation of the mind as something distinct from the physical brain. This dualism may be adapted to create the similar notion of the soul, as used by religions. The mind or the soul is the agency that to some extent or another exists or emerges out of the human brain and body; and familiarity prevents us accepting that we are totally physical entities.
This notion of mind, soul, or even self, conscious self, identity, seems to be a natural instinct that on the face of it appears difficult for the physicalist to explain. What seems clear to a physicalist, particularly one that also accepts Darwinian evolution as a satisfactorily explained process, is that this notion of agency has been projected, extended, by human creative imagination, to hypothesise the existence of gods. But from the physicalist evolutionary point of view there seems little doubt that this God is made in man's image, not man in his. God is a construct of the human imagination.
If we imagine and follow the developmental and evolutionary path, from physical inanimate objects, to the first replicators, through simple life forms, lesser animals, mammals, primates, and on to man, it is clear that there is no evidence of any mechanism, or any intervention, that suddenly switches on or enables agency. Agency, like free-will, and consciousness, are illusory, so the physicalist hypothesis goes. They are simply hypothetical models of complex systems in action. The fact that we, in the complex biological process of responding to our environment and our current inner physical (chemical and electrical brain system) state, respond as if we are agents, as if we have free-will and consciousness, is merely an efficient mechanism that helps us to operate.
Watch the video clips of the 'insects' created by Robert Full's and other teams. I challenge you not take an inner or explicit gasp as you inevitably look on these machines as being alive in some crude sense - that is your agency recognition system kicking in and recognising agency where there is none. We recognise agency in ourselves, in other animals, in some robots, in cartoon characters, in toys. We are built to perform this recognition of agency.
Did I say "We are built to perform this recognition."? See? "We are built..." We are not built, in the active sense that someone built us. That's precisely the point. We can't help but think in this way. Richard Dawkins did the same throughout his book The Selfish Gene - his actual words, the title, imparted apparent agency upon genes, when of course this is precisely what he didn't intend. We use phrases implying agency all the time, even when that's exactly what we are arguing against. The phrase "We evolved (intransitive) to do ..." itself could be interpreted as "We actively, through our own will, evolved (caused) ourselves to do ...", or as "We were evolved (transitive) by the agency of Evolution itself to do ..." Our language is so evolved to inherently assume agency we have to resort to quite contrived language to describe the physicalist view without agency. So, when talking about something I do, to make it clear there is no intention and free-will in my action I have to resort to words like, "This complex responding organism (me) responded in such a way..."
Agency is a vehicle that gets us through the journey of life efficiently and quickly. But we need to get out of this vehicle now and then and ruminate in the grass, stroll through the woods, take in the view. Once we park agency on the road side we can proceed to walk carefully through life examining in more detail the arguments that tell us that agency is all there is, and just suspend that notion. Simply review the arguments as if there is only physical stuff; put agency to one side.
Some theists will happily tell you how necessary God is to explain the physical universe - he's the first cause, he's infinite, etc. But let a physicalist propose that the universe might be infinite, or that there might be multiple inanimate universes, with no agency, and the theists will ask how this is possible. They will raise paradoxes that physicalism appears unable to explain. But there really is no difference between any hypothesised cause of the universe, whether it be theistic or physicalist - except for the presence or absence of agency. Both theists and physicalists have to struggle with the fact that they don't know what lies beyond the known; we don't know if it's infinity all the way or not; it's hard enough to be sure that the concept of infinity has any significance, any reality. So, the only difference between any proposed God creator and an equivalent non-theistic beginning is the presence of God as the agent.
But if there is no concrete evidence for agency's instantiation, no evidence of it springing into existence, then there is really no argument for it existing outside the universe, as God. And since we are the only agents we do have evidence for, if we figure we are complex stuff but not agents, then there is no known concrete evidence of agency anywhere.
Now, having said all that I'm still happy to use terms like agency, free will, consciousness, mind, etc., as creative notions, as convenient models, for complex physical systems and processes, like ourselves. I'm happy to say "evolution built us this way" without any teleology implied. It's how I've evolved to think, so i can't help it.