That's his incoherent belief system, as far as I can tell too. I wanted to at least make clear that he and us have different definitions of God. So if we're going to argue over God's existence, we should at least agree on a definition of God.
How to prove the existence of the non-material to a materialist? I prefer a negative proof. If an atheist can understand that materialism is self-contradictory, then he will logically have to accept the existence of the spiritual.
The internal contradictions in materialism lie in epistemology. Peter Kreeft lays out the arguments nicely in his Handbook of Christian Apologetics.
1) If everything is material, then the thoughts in our heads are simply the result of randomly colliding atoms. If this is the case, then my random "thought" that materialism is false and lexcorp's random "thought" that materialism is true are equally valid since they are both the result of the random collision of atoms. But this violates the Law of Non-Contradiction. So the premise must be false. Therefore materialism is false.
2) Stated another way, if we live in a purely material universe then we are machines. If we are truly machines, then we can malfunction. Therefore, there is no logical way for me to know whether my beliefs are true or false with either certainty or probability. Therefore, I cannot logically make any truth claims including the assertion that "materialism is true." Moreover, there would be no logical way for me to know whether the Law of Non-Contradiction is true. But we know that the Law of Non-Contradiction is true. Therefore, the premise must be false, and materialism must be false.
3) Materialism cannot account for the self. What am "I"? Can I be reduced to the material? Am I identical with my body? If so, am I 3/4 of a person if I lose an arm? Do I become a different person each time a cell in my body dies? But this contradicts experience.
What about consciousness? Is it a collection of thoughts (chemical secretions) in my brain? But consciousness is a unitary experience and the opposite of a group of many discrete chemical secretions.
Does a material scanning mechanism in the brain monitor and bring together discrete thoughts (chemical secretions)? But then there would be as many selves as acts of scanning, and the unitary self dissolves once more. My consciousness is a unitary experience and cannot be accounted for by materialism. Therefore materialism must be false.
These arguments disprove materialism with certainty. Unfortunately, materialists rarely follow their own philosophy to its illogical conclusions, and often rest their arguments on unrecognized spiritual assumptions.
Finally, materialists should be made to define "truth." The only coherent definition of truth is the Aristotelian/Thomistic definition. Any materialist definition of truth cannot overcome the knower/thing known gap, logically resulting in universal skepticism (which is internally contradictory) or solipsism (which is contradictory by experience).
I rarely find a materialist willing to follow the arguments this far before bailing out. They seem to see the logical conclusion coming and, in fear, lapse into emotional attacks against the arguments.
A very helpful point. I was sensing a logjam, but your clear thinking identified what the problem is and how to overcome it: a common-ground definition of God. If that is not possible, other arguments will be muddled, at cross purposes, talking past each other, reduced to the trite, some of all of the above . . .
unrecognized spiritual assumptions
"Faith in science" logically falls into this category, since faith in science is still faith and not science.
materialists should be made to define "truth."
The entire ediface of science depends upon truth as a property of the matierial world: existing, being discoverable, and repeatable/verifiable . . . Materialists should be defending truth "in season and out of season", not allowing science to potentially wither by allowing its roots (knowable truth) to be pruned off . . . which is what relativism does . . . I had to respond to an article in a publication which threatened to lead practical people (business managers and Industrial Engineers) to the unjustified (and untrue!) conclusion that quantum mechanics means everything is uncertain. . . we might as well throw up our hands and give up in that case, and stop trying to build buildings and discover the unknowns in particle physics and etc. . . . muddled thinking has consequences . . .
People are in so many different places on their journeys of discovery to truth, and honestly setting out upon that journey in itself engenders respect.