I loved this quote from Jeffery Bradshaw’s talk at the 2014 Temple on Mount Zion Conference. I’ve been trying to find a way of saying the same thing, but now I can just quote someone who hit the nail on the head.
“It is my personal witness that the LDS temple ordinances are, as Elder John A. Widstoe affirmed, “earthly symbols of realities that prevail throughout the universe” they point to heavenly meanings beyond themselves – meanings that can be revealed through our “minding true things by what their mock’ries be.” The ordinances perform an essential earthly function, helping make us ready someday to behold the face of God as did Moses. Indeed, those who participate in the ordinances of the temple are shown in ritual what Moses and others throughout ancient and modern history have experienced in reality.” (Jeffrey M. Bradshaw, ”What Did Joseph Smith Know about Temple Ordinances by 1836?”) https://www.youtube.com/watch?v=UhQWrMXt2Mc#t=1856
The temple endowment, has become to appear more and more like a symbolic version of the great visions experienced by the ancients like Enoch, Abraham, Moses, Isaiah, Nephi, Mahonri (the brother of Jared), etc.
Some of the themes we see are the creation story, ritual cleansing and clothing, ascension and an invitation into the presence of God. The temple endowment appears to be, at least on one level, a gift from God to help us prepare to receive the same experiences.