Other words instead of mystical might be transcendent, otherworldly, mysterious. Ellen White used the word mystic* to describe the ladder in Jacob's dream that reached from Earth to heaven. I feel comfortable then, using a word that some traditional folk might not like to use about Christianity.
What I mean is that it takes a lot to believe in all these non-tactile realities and historical occurrences. Rationally speaking it makes no sense. But reason is not always the most important reality in the world; or it need not be.
This dawned on me as I drove home in a cool afternoon without any cares in the world. This was in spite of the fact that I had just spent $900 to have new wheels put on my car and other automobile expenses. Where was I going to get that money to pay down the credit card bill? I didn't care. I would let God take care of that essential expense. Worrying about it was not going to pay it off any faster. God knows I had to have those tires and the other parts that were defective. He knows, also, that I need to find the funds to pay off this negative cash flow expense.
Back home, I spent what I thought was going to be only 30 minutes reading about the Christian life, but I got so engrossed in the experience that when I looked at the clock, almost two hours had come and gone. I wanted to continue reading more of Steps to Christ, but I realized that I had other things to do before Sunday became Monday morning.
I had been invited to a Christmas party--the only one this year so far. I was unsure of whether to go as there was going to be alcoholic drinks there and other non-Christian influences that may or may not turn out to be deleterious to my experience. I prayed about it and decided that that was one party that I was better off not attending. Now, it might have turned out just fine, but I felt moved not to take a chance. Instead I spent the afternoon reading and meditating about God's amazing grace. That defies reason in most people's minds. I does in mine.
There's no other explanation other than that Christianity is mystical. How else to account for spending good quality time on a Sunday afternoon reading Steps to Christ when so many other things beckoned?
* mysterious: having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding; ". . . someone who believes in the existence of realities beyond human comprehension wordnet.princeton.edu/perl/webwn