Joseph Smith introduced and described the endowment as follows: “Wednesday, [May 4, 1842]—I spent the day in the upper part of the store…in council with General James Adams of Springfield, Patriarch Hyrum Smith, Bishops Newel K. Whitney and George Miller, and President Brigham Young and Elders Heber C. Kimball and Willard Richards, instructing them in the principles and order of the Priesthood, attending to washings, anointing, endowments and the communication of keys pertaining to the Aaronic Priesthood, and so on to the highest order of the Melchisedek [sic] Priesthood, setting forth the order pertaining to the Ancient of Days, and all those plans and principles by which any one is enabled to secure the fullness of those blessings which have been prepared for the Church of the First Born, and come up and abide in the presence of the Eloheim in the eternal worlds. In this council was instituted the ancient order of things for the first time in these last days. And the communications I made to this council were of things spiritual, and to be received only by the spiritual minded: and there was nothing made known to these men but what will be made known to all the Saints of the last days, so soon as they are prepared to receive, and a proper place is prepared to communicate them, even to the weakest of the Saints; therefore let the Saints be diligent in building the Temple, and all houses which they have been, or shall hereafter be, commanded of God to build; and wait there time with patience in all meekness, faith, perserverance unto the end, knowing assuredly that all these things referred to in this council are always governed by the principle of revelation.” (Doctrinal History of the Church, 5:1-2).
This is perhaps the best description of the endowment left by Joseph Smith. I believe it is worth careful reading and solemn pondering.