What Is Priesthood? Powers of Heaven

D&C 121:36 That the rights of the priesthood are inseparably connected with the powers of heaven and that the powers of heaven cannot be controlled nor handled only upon the principles of righteousness

This is the priesthood. Lets examine this piece by piece. What are these "rights".

9 And I will make of thee a great nation, and I will bless thee above measure, and make thy name great among all nations, and thou shalt be a blessing unto thy seed after thee, that in their hands they shall bear this ministry and Priesthood unto all nations;
10 And I will bless them through thy name; for as many as receive this Gospel shall be called after thy name, and shall be accounted thy seed, and shall rise up and bless thee, as their father;
11 And I will bless them that bless thee, and curse them that curse thee; and in thee (that is, in thy Priesthood) and in thy seed (that is,thy Priesthood), for I give unto thee a promise that this right shall continue in thee, and in thy seed after thee (that is to say, the literal seed, or the seed of the body) shall all the families of the earth be blessed, even with the blessings of the Gospel, which are the blessings of salvation, even of life eternal. (Abraham 2:9-11)

Abraham is blessed with "this right" that it shall continue in thee (that is in thy priesthood). What was this right? The right is associated with Abrahams promise. The defintion of "rights" is "entitlement".The promise is that all those who receive "this gospel" shall be called after thy name (Abraham), and shall be accounted thy seed (Abraham). Also it associates "in thee" with "thy seed" with 'thy priesthood". Are these the same thing? Is it that "priesthood" comes from "seed" or "posterity" or "powers'? The right he received was that his seed shall have the blessings of salvation, even life eternal. It was through that right, that his seed or "thy priesthood" would endure.

Lets look at "continue" in D&C 132.

31 This promise is yours also, because ye are of Abraham, and the promise was made unto Abraham; and by this law is the continuation of the works of my Father, wherein he glorifieth himself.

22 ...narrow the way that leadeth unto the exaltation and continuation of the lives [lives, or thy seed, or thy priesthood, this extends not to yourself only but those of your posterity or powers]

19 ...and they shall pass by the angels, and the gods, which are set there, to their exaltation and glory in all things, as hath been sealed upon their heads, which glory shall be a fulness and a continuation of the seeds forever and ever.

What are the works of the Father?

39 For behold, this is my work and my glory—to bring to pass the immortality and eternal life of man. (Moses 1:39)

So the blessings or "entitlements" of the priesthood are inseparably connected with the "powers that are in heaven".  So we use this verse to define "priesthood" often in the church.

Powers that are IN heaven
What are the powers that are in heaven? Lets examine a bunch of scriptures.

Mark 13:25 And the stars of heaven shall fall, and the powers that are in heaven shall be shaken. 

Moses 7:27 And Enoch beheld angels descending out of heaven, bearing testimony of the Father and Son; and the Holy Ghost fell on many, and they were caught up by the powers of heaven into Zion. 

3 Nephi 20:22 And behold, this people will I establish in this land, unto the fulfilling of the covenant which I made with your father Jacob; and it shall be a New Jerusalem. And the powers of heaven shall be in the midst of this people; yea, even I will be in the midst of you.

Lets look at some Aposcypha.

[God] spake the word, and they all came into being, Angel, and Archangel, and Cherubim, and Seraphim, and Thrones, and Divine Governors, and Dominions, and all the Powers that are in the heavens, and all the army of heaven. (Discourse of Abbaton, here) 

Do you see how the Powers of Heaven are associated with angels? With the heavenly hosts of God? Or as his name states the Lord of hosts? Another way to phrase this would be the Lord of the Powers of Heaven. Or Lord of "thy seed" or "thy priesthood".

Powers of Satan
This next verse talks about a different type of "powers", those of satan. The 1/3 part that were cast out. Do you see how these angels are associated with "powers". "powers of the earth" or as before it was "powers of heaven".

39 Now this change was not equal to that which shall take place at the last day; but there was a change wrought upon them, insomuch that Satan could have no power over them, that he could not tempt them; and they were sanctified in the flesh, that they were holy, and that the powers of the earth could not hold them (3 Nephi 28:39)  

11 For all flesh is corrupted before me; and the powers of darkness prevail upon the earth, among the children of men, in the presence of all the hosts of heaven—
12 Which causeth silence to reign, and all eternity is pained, and the angels are waiting the great command to reap down the earth, to gather the tares that they may be burned; and, behold, the enemy is combined. (D&C 38:11-12)

Lets look at a source written by a Catholic member who pulls from some Apocrypha.

There were defections, probably, from almost every Choir of the heavenly Hierarchies. Saint Paul mentions Principalities and Powersamong the fallen angels, who try to seduce man with their deceits: "Put you on the armor of God, that you may be able to stand against the deceits of the devil. For our wrestling is not against flesh and blood, but against Principalities and Powers, against the rulers of the world of this darkness, against the spirits of wickedness in the high places."[45] As Saint Paul never gives a complete enumeration of all the Choirs of the good Angels at one time, we may surmise that he follows the same rule with the fallen angels. The mention of Principalities and Powers in this passage should not be taken as complete and exclusive, but only as more representative and as implying the great natural power and cunning of our adversaries. Even though deprived of all supernatural grace and superadded gifts, the fallen angels retain their natural power which, in itself, is far superior to the natural power of man. For this reason the Apostle demands that the faithful put on the "armor of God" and "the shield of faith" in order to be able to resist and to conquer. Yet, in view ofthe fact that in another list of fallen angels, the Apostle mentions again only these two Choirs: Principalities and Powers, we believe that the largest number of fallen angels must have come from them. Speaking of Christ's victory over sin and the Devil, Saint Paul says: "Despoiling the Principalities and Powers, he hath exposed them confidently in open show, triumphing over them in himself "[46] (Chapter 3 of the book The Angels, by Pascal P. Parente., here)

The Discourse of Abbaton (cited above) also says this about Satan, or his powers.

"Thou shalt shew compassion neither upon small nor great, and thou shalt carry all away mercilessly. The Powers shall be under thy control, and thou shalt send them after every soul.

Wikipedia states in the article on Christian angelic hierarchy.

The Powers are the bearers of conscience and the keepers of history. They are also the warrior angels created to be completely loyal to God. Some believe that no Power has ever fallen from grace, but another theory states that Satan was the Chief of the Powers before he Fell (see also Ephesians 6:12). Their duty is to oversee the distribution of power among humankind, hence their name. 

Their duty is the distribution of power among human kind. "by the voice of heaven" we receive the power of the priesthood. Or through our connection to these powers (heavenly hosts) we gain Power in the "Priesthood" or thy seed. Or Gods Seed or Abrahams seed. Abraham's Priesthood perhaps than is "Abrahams Powers". It can only be given to us from God Himself.

Lets look at the Book of Enoch and what Hugh Nibley said about Satan. This is published in the Ensign and it was a summary of the book that Hugh Nibley wrote. This is Part 8 of the series.

"God saw that Satan, because of his boundless ambition and total lack of humility, could no longer be trusted with celestial power and commanded the angels to remove him from his office. This ordinance they performed with great sorrow and reluctance: They “removed the writing of authority from his hand. They took from him his armor and all the insignia of priesthood and kingship.” Then with a ceremonial knife, a sickle, they inflicted upon him certain ceremonial blows of death which deprived him of his full strength forever after. (14a.) Other accounts say that after these cuts he retained only one-third of his former power, even as he was followed by one-third of the hosts".
https://www.lds.org/ensign/1976/12/a-strange-thing-in-the-land-the-return-of-the-book-of-enoch-part-8?lang=eng

Hugh Nibley in another source has said Satan was stripped of his power or priesthood "member by member".

Knowledge to Subject Satan

Do you see now how the keys of the kingdom are associated with signs that the elders must know to detect false spirits? Or thist kind of knowledge (keys) are associated with "priesthood"?

I preached in the grove on the keys of the Kingdom, Charity &c The keys are certain signs and words by which false spirits and personages may be detected from true, which cannot be revealed to the Elders till the Temple is completed--The rich can only get them in the Temple, the poor may get them on the mountain top as did Moses. The rich cannot be saved without charity, giving to feed the poor when and how God requires, as well as building. There are signs in heaven, earth and hell: the Elders must know them all, to be endowed with power, to finish their work and prevent imposition. The devil knows many signs, but does not know the sign of the Son of Man, or Jesus.

Or how knowledge ties into this.

A man is saved no faster than he gets knowledge for if he does not get knowlede he will be brought into captivity by some evil power in the other world as evil spirits will have more knowledge & consequently more power than many men who are on the earth. hence it needs Revelation to assist us & give us knowledge of the things of God. What is the reason that the Priest of the day do not get Revelation They ask ownly to consume it upon their lust their hearts are corrupt & they cloak their iniquity by saying that their is no more Revelations But if any Revelations are given of God they are universally opposed by the priest & christendon at large for it reveals their wickedness & abominations

Lets look at one more source.

The POWERS are so called because they have power over the devil, in order to restrain the power of the demons, to repulse the temptations brought upon people by them, and to prevent the demons from harming anyone to the degree that they would wish. The powers strengthen the good ascetics in spiritual struggles and labors, protecting them so that they may not be deprived of the spiritual kingdom. They help those wrestling with passions and vices to cast out evil thoughts and slanders of the enemy and to conquer the devil. (The Holy Angels, here)

The Order of Heaven 

In the scheme of things Jesus Christ is far above these other creations. So Paul knew something about the order in heaven since he had been there in vision. (2 Corinthians 12:3)

Remeber this quote above from the Abbaton?

[God] spake the word, and they all came into being, Angel, and Archangel, and Cherubim, and Seraphim, and Thrones, and Divine Governors, and Dominions, and all the Powers that are in the heavens, and all the army of heaven.

Its giving us a key of the different type of "Powers" in the heavens. There are many scriptures in D&C and the book of Mormon that talk about these different types search them. Post is already too long so I won't do it.

The Gods:
Powers in Heaven...
Micha El
Rapha El
Gabri El
Uri El

El means God.

And the voice of Michael, the archangel; the voice of Gabriel, and of Raphael, and of diversangels, from Michael or Adam down to the present time, all declaring their dispensation, their rights, their keys, their honors, their majesty and glory, and the power of their priesthood; (D&C 128:21)

Study Abraham 3-4.

Handled by Righteousness
Do you see now why "the powers of heaven cannot be controlled nor handled only upon the principles of righteousness."? We cannot control these "Powers" unless its by "persuasion, longsuffering...". The heavenly hosts are for the most part (but not only) the hosts of the city of Enoch. As soon as we attempt to do anything contrary to the way its meant to be handled we lose the connection to heaven, unless we repent.

The "power" of the angels "over the nations of the earth" (D&C 77: 11) is needed to prevent Zion from being overrun or destroyed by the nations of the earth. These other nations, if they oppose Zion, will be destroyed. (Daniel 2: 31-45; D&C 87: 6.) The "powers of heaven" which will hover over Zion will discourage any army from battling her. (D&C 45: 70.)

This is why Zion cannot be built without the Fulness of the Priesthood. And why so few have ever built up Zion. They were unworthy and incapable of receiving this priesthood. Joseph and Sidney joined the holy angels who stood before God. (D&C 76: 21.) Therefore, they would be among those who "came to an innumerable company of angels, to the general assembly and church of Enoch, and of the Firstborn." (D&C 76: 67.)

Both male and female can have this same fellowship. Do you see what it means to call upon the "Powers of heaven" or to call upon the priesthood of God, because His priesthood are His hosts or "Powers". 

If you didn't get the message
Hood: Neighborhood, motherhood, fatherhood, sisterhood... Its an association of a group of people.

Priesthood is always a relationship between man on earth and the "powers" or hosts of heaven. These angelic or heavenly beings were those who escorted men to the first heavenly Zion (Moses 7: 27), and will do so again.