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.
Perhaps you have more confidence then that a teacher of math, etc. is more competent than a preacher, even though you will have to take on faith most of what he teaches. After all, a teacher of math these days can teach imaginary numbers.
Truth is not subjective, but is always Truth. If the Holy Spirit abides in you, you will have no problem discerning Truth. In fact, it will be really easy to determine false prophets. Only when the HS is not indwelling does one run here and there to hear some new thing.