There are three kinds of mysteries. The mysteries of godliness, by which men become more like God. Faith, hope and charity are the chief among these. Next are the mysteries of creation. If the mysteries of godliness are the similar to knowing how to live in a house, the mysteries of creation are similar to knowing how to build a house (most people think of these when they think of "mysteries"). Finally there are the mysteries of salvation, which include the temple.
There is much to be said about the temple. Most of the "public" discussions come from the writings and addresses of Hugh Nibley following the Manti Temple seminars/discussion group he had that was commissioned by the first presidency for the consideration of the temple in the 1970s that led to the clarifications and emendations in the temple as we have it today.
Some of the matters are simple. In the Egyptian endowment one passes between worlds or stations by boat. In the Chinese/Triad mysteries one passes through the stations by crossing bridges. As one can see in the books illustrating and displaying the Salt Lake and Manti temples, one passes between worlds or rooms by passing through doorways and past thresholds. A modern temple uses much more subtle indicators.
Or consider what the stations indicate. In historic studies of temples and similar rituals and heroquests there are the five wounds of death that are recovered from/healed on the way to resurrection and there are four breaths that lead to eternal life. Through the very early 80s, Nibley was known to favor the five wounds of death interpretation. There is reason to believe that he changed over to the four breaths (the last of which is gained in the resurrection).
Finally there is the question of the relationship between men and women and what the temple means by it. We do know that many general authorities and a number of prophets have taught that men and women are equal and that any man that thinks he has a right by means of the priesthood to control his wife or have the final word has lost the priesthood (look at some of the talks on that topic vis a vis D&C 121).
There are also a good number of sermons, informed by temple attendance, indicating that what inequality that exists between the sexes is the result of the fall and is to be overcome by means of the temple, not instituted thereby. Nibley gave some very interesting public addresses that brushed against this concept or that taught it directly, prior to his involvement in the rectification of the ceremony vis a vis earlier texts and lectures by Brigham Young, Joseph Smith and others.
Of course one is free to find an unmediated revelation in what God intends each person to learn, which is part of the essence of the temple, but it is relevant to consider what the most recent editors and emendations intended and taught in finding an understanding of how we are informed and inspired by the temple.
Next week I'll try to come back to Utopias and why we don't recognize them when we encounter working utopias in the modern world. I also have a post pending on how to complain without sounding like the mentally ill. But the temple is the heart of Zion, so I've taken a moment to discuss the mysteries of the kingdom, salvation and the temple on the way to discussion of Utopia.