"Now Melchizedek was a man of faith, who wrought righteousness; and when a child he feared God, and stopped the mouths of lions, and quenched the violence of fire.
"And thus, having been approved of God, he was ordained an high priest after the order of the covenant which God made with Enoch, It being after the order of the Son of God; which order came, not by man, nor the will of man; neither by father nor mother; neither by beginning of days nor end of years; but of God; And it was delivered unto men by the calling of his own voice, according to his own will, unto as many as believed on his name.
"For God having sworn unto Enoch and unto his seed with an oath by himself; that every one being ordained after this order and calling should have power, by faith, to break mountains, to divide the seas, to dry up waters, to turn them out of their course; To put at defiance the armies of nations, to divide the earth, to break every band, to stand in the presence of God; to do all things according to his will, according to his command, subdue principalities and powers; and this by the will of the Son of God which was from before the foundation of the world.
"And men having this faith, coming up unto this order of God, were translated and taken up into heaven. And now, Melchizedek was a priest of this order; therefore he obtained peace in Salem, and was called the Prince of peace.
"And his people wrought righteousness, and obtained heaven, and sought for the city of Enoch which God had before taken, separating it from the earth, having reserved it unto the latter days, or the end of the world; And hath said, and sworn with an oath, that the heavens and the earth should come together; and the sons of God should be tried so as by fire.
"And this Melchizedek, having thus established righteousness, was called the king of heaven by his people, or, in other words, the King of peace." (Genesis 14:26-36, Inspired Version)
When Joseph and Oliver commissioned and ordained twelve Apostles, there were told they were not actually Apostles until they had obtained their own knowledge of Christ. When one is baptized by water, they are not baptized by fire until a time of God's choosing. When one goes through the veil of the temple, the person does not enter heaven on the other side until they actually fulfill the blessings offered to them in the temple. When one is ordained to the Melchizedek priesthood, he does not actually have that most Holy Priesthood until he proves himself acceptable and God Himself gives it to him.
"For there is not a place found on earth that he may come to and restore again that which was lost unto you, or which he hath taken away, even the fulness of the priesthood....But I command you, all ye my saints, to build a house unto me; and I grant unto you a sufficient time to build a house unto me; and during this time your baptisms shall be acceptable unto me. But behold, at the end of this appointment your baptisms for your dead shall not be acceptable unto me; and if you do not these things at the end of the appointment ye shall be rejected as a church, with your dead, saith the Lord your God." (D&C 124:28, 31-32)
The Mystery of the Priesthood, Angels Cannot Understand It
"The endowment you are so anxious about, you cannot comprehend now, nor could Gabriel explain it to the understanding of your dark minds." (Joseph Smith, HC 2:22, p. 309)
"The mystery power and glory of the priesthood is so great and glorious that the angels desired to understand it and cannot: why, because of the tradition of them and their fathers in setting up stakes and not coming up to the mark in their probationary state." (Joseph Smith, 27 August 1843, Words of Joseph Smith, p. 247, James Burgess Notebook)
"King of Shiloam-power & authority over that of Abraham holding the key & the power of endless life.-angels desire to look into it, but they have set up to many stakes. god cursed the children of Israel because they would not receive the last law from Moses." (Joseph Smith, 27 August 1843, Words of Joseph Smith, p. 244, Willard Richards Diary)
There are three priesthoods: Aaronic, Melchizedek and Patriarchal. To be rightly called a priesthood, they must include associations with the powers of heaven.
This priesthood was given for condemnation; to seal up the children of men to the hardness of their hearts, or to lift them. When the children of Israel refused to come into the presence of God they were cursed with this lesser priesthood. This priesthood includes the association of angels which include true messengers that have authorized messages. Isaiah, Ezekiel, Jacob, King Benjamin and Joseph Smith are examples of these. The office of the calling of angel is to call men to repentance, to declare the conditions of repentance such that they may enjoy a greater priesthood if they are true and faithful.
Melchizedek (The Holy Order after the Order of the Son of God)
This priesthood is an association with the Savior or Second Comforter. It is not obtained by father or mother or by the will of men, but comes directly from God himself who employeth no servant there. The purpose of this priesthood is to help those who are true and faithful to enjoy a greater priesthood.
This priesthood brings us into association with the Great Patriarch, God the Father. We see an example of this priesthood when Nephi is having a dialogue with both the Father and the Son.
Joseph sought for the saints to obtain these last two priesthoods, which they had previously forfeited. The Lord set the conditions, and Joseph delivered the conditions of repentance to the saints. Those conditions were never fulfilled. (D&C 124)
These associations, or priesthoods are not limited to men, and indeed cannot be obtained by men without a woman.
We can continue to assert that the Nauvoo saints were faithful and that we have a fulness now, but by doing so we damn ourselves because we do not seek for what we could obtain, by the means appointed to obtain them.