If this were uniformly tossed then no Scripture would ever be taught. As there is no private interpretation of the scripture, (2 Peter 1:20) and faith comes from hearing and hearing from the Word of God (Romans 10:17), Christianity would cease to exist.
As for all reality being an illusion, actually, according to the bible, it is not. You have the seen world, in which we live, and exist through laws, in an orderly manner, and you have the unseen world, the invisible (Romans 1:20, Col: 1:15,16, 1Titus 1:17, Hebrews 11:27 ) all created at the same time and both worlds are the Creation.
The pull and flow of the quantum fields may perhaps look like illusion, but the world is still the same world that was created by God, and a Buddhist or a Hindu contemplating his own mind, and thinking that all is illusion, does not disappear, and more importantly he does not "find" God, only his own mind's vain imaginings. God cannot "be found".
I very very strongly agree that God cannot be "found" by any mental reasoning, meditation or other effort of man. Nor can man be "good enough" to get to heaven - if he could have, then Christ died for nothing. (Galatians 2:21)
I also very strongly agree with you that there is a "seen" world and an "unseen" - or a physical and a spiritual, an earthy and a heavenly. My point was one of confidence - if a person is more confident or sure of the physical than the spiritual he risks becoming a "doubting Thomas".
But then again, doubting Thomas was an apostle, too.
But if his commentary does not rely on the Spirit but rather is based on his own mental reasoning using maps, logic, committees, documents and the ilk - his comments are spiritually worthless to me for the very reason that God cannot be "found" by reasoning, meditations, etc. as you say.
The comments of such a one may be useful for other purposes however - science, math, history, philosophy, etc.