OKAY, THIS MAY SOUND A BIT TOO HONEST, BUT REALLY, I'VE GOT TO SAY IT!
Kelby, I couldn't agree with you more! They can't understand spiritual things because they are trying so hard to sound so intelligent with their natural minds, perhaps to impress others, I don't know their motivation, but the reality is that they don't know ANYTHING! That's why I think it's almost a waste of time to discuss this topic with people who obviously have a closed mind, heart and spirit. They only attack, accuse, and claim superior knowledge of something they know NOTHING ABOUT! Quite ARROGANT really, when you think about it!
{Let's suppose for a moment that I had to examine and write a review of a picture of a bumblebee(as if I'd never seen a real bumblebee before in my life). I would probably laugh outright, because in my "expert opinion", it was so obviously a creature that could have never flown...like the ostrich. I would logically point out that the size of their wings were disproportionate to their bodies, rendering them unable to lift their chubby body in flight, or sustain it in mid air. And, I'd probably think that people who believed otherwise were foolish to think that the bumblebee could ever fly or could have ever been that useful in the first place. Basically, an unimportant gift to humanity, not worthy of attention.}---in like manner, such is the critique given about this gift from people who know NOTHING about it, or any other gift, for that matter.....BUT HEY, it's their "expert opinion".
NOW, the reason I also agree with you about trying to understand things with our natural mind and limited experience is that something similar also happened to me.
As a preface to this, and if you are interested, my testimony:"Truly Unexpected" gives an account of when God became a living, breathing God to me, and it was also when I received the gift of tongues. But moving on, after that, my experience was definitely very, very limited, and wanting to learn more, I picked up a bible study book written by Kenneth Hagin (senior), a former Baptist turned pentecostal preacher. The book was about all the gifts of the spirit. And well, try as I might, I could NOT understand much of it...and that's even with Pastor Hagin repeating himself in the book quite a bit...and by the way, I usually get stuff I read the first time around! It was not until I went on a missionary trip to the Bahamas years later that I saw the gifts in action in me and in others that I finally understood what that bible study book meant! ...and bible passages as well. I can't explain it, it's like it suddenly seemed so simple and perfect when before it seemed like gibberish.
So yes, there are some things that can only be understood in the spirit....IF you are open to understanding them...BIG IF.