Fletcher was Wesley’s European successor, and designer of the program that eventually became the Methodist denomination(s). His essay on Evangelical Mysticism is a must, I think.
Our current crop of evangelicals, and those to the right, tend to think in plain sense terms — that is, that Scripture is so plain, that it is easily understood. Yet, 2000 years of Christian Tradition should teach us otherwise. This is why we have theologians and teachers, to expound Scripture. Further, given that all words are mere symbols for larger truths, we have to understand that it takes thinking to get to the deep things of God.
Add to this the need for oversimplification in modern Western Christianity. There is no mystical element, or rather, we are doing our best to remove the mystical elements of the words of our holy books.
The challenge is this: how do you illuminate Scripture to the minds today?
Think of it is this. The writer of Ephesians uses an allegory of marriage to represent Christ and the Church. This is deep, because we can invest in it all sorts of right things, coming to understand covenant, love, and even submission.
Throughout the Old Testament, each moral command is given to us in metaphor, so that we understand that “do not murder” is something behind the taking of a life. Relate it to Cain and Abel. Understand what it means that when one is murdered, the entire cosmos groans. How precious, then, is life to God?
I could go on, but I want to encourage those who are making moral demands, to remember the words of Fletcher. The metaphor explains the why.