If the reality of spirit and the reality of free will cannot be encountered in ourselves, in the depths of our subjectivity, why should we think that they can be encountered outside ourselves -- in God, for example?
I don't understand those who attempt to combine theism with materialism about the human mind. I don't deny that it is a logically possible combination. But mere absence of formal-logical contradiction is no guarantee of metaphysical coherence. (I develop the thought in "Could a Classical Theist be a Physicalist?" Faith and Philosophy, vol. 15, no. 2, April 1998, pp. 160-180.)
If reality has a spiritual core we will be able to learn about it only by studying ourselves, by plumbing our subjective depths, not by reducing self to not-self, not by trying to understand spirit and consciousness in material terms. They cannot be understood in those terms, and attempts to do so end up eliminating the very means of access -- mind and language -- to the material world.