Priesthood

"We who have been called to lead the Church are ordinary men and women with ordinary capacities struggling to administer a church which grows at such a pace as to astound even those who watch it closely. Some are disposed to find fault with us; surely that is easy for them to do. But they do not examine us more searchingly than we examine ourselves. A call to lead is not an exemption from the challenges of life. We seek for inspiration in the same way that you do, and we must obey the same laws which apply to every member of the Church. We are sorry for our inadequacies, sorry we are not better than we are. We can feel, as you can see, the effect of the aging process as it imposes limitations upon His leaders before your very eyes. But this we know. There are councils and counselors and quorums to counter-balance the foibles and frailties of man.The Lord organized His church to provide for mortal men to work as mortal men, and yet He assured that the spirit of revelation would guide in all that we do in His name. And in the end, what is given comes because the Lord has spoken it, 'whether by [His] own voice or by the voice of [His] servants, it is the same' (D&C 1:38). We know His voice when He speaks. Revelation continues with us today. The promptings of the Spirit, the dreams, the visions and the visitations, and the ministering of angels all are with us now. And the still, small voice of the Holy Ghost 'is a lamp unto [our] feet, and a light unto [our] path' (Psalm 119:105). Of that I bear witness, in the name of Jesus Christ, amen."
(Boyd K. Packer, CR, Oct. 1989, p. 19)

All of the following were said by Robert J. Matthews and titled "Facts About the Priesthood."
1. There was one priesthood from Adam to Moses. It was called The Holy Priesthood after the Order of the Son of God (D&C 107:3).
2. All Priesthood is Melchizedek, and contains two levels (See T. 180).
3. There is no hereditary requirement for the Melchizedek Priesthood (See T. 323).
4. The Levitical Priesthood is forever hereditary--fixed on the head of Aaron and his sons forever (See T. 319).
5. The Aaronic Priesthood was needed to administer the law of Moses and the law of carnal commandments. It was a lesser priesthood for a lesser law; a preparatory law of performances and ordinances until Christ (Mosiah 13:29-31).
6. The Law of Moses was a good law, by a good prophet, and had divine priesthood. It was atonement-centered, adapted to a people not ready for the fulness of the gospel.
7. Only the sons of Aaron could have fulness of the Aaronic Priesthood. They became priests and high priests. Other Levites (not of Aaron) could hold lesser offices of Aaronic (Levitical) priesthood. 8. The priests and Levites were designated for offering sacrifices and temple service.
9. The hereditary nature of Aaronic Priesthood is still in force and will have part in the restoration (See T. 319; Ex. 30:30-31; 40:13-16).
10. The fact there were no Levites among the Nephites, yet the law of Moses was functional, is evidence that the Nephites had the Melchizedek priesthood.
11. A Bishop has to be a Melchizedek high priest unless he is a descendant of Aaron (D&C 68:14-21).
12. The Aaronic Priesthood was among the Jews from Aaron to John the Baptist in an unbroken line (D&C 84:26-27).
13. John the Baptist was the living embodiment of the law of Moses--a schoolmaster to lead people to Christ. He literally introduced many to the Messiah.
14. John was the legal high priest, a firstborn descendant of Aaron, holding the keys of the Aaronic Priesthood.
15. Apostate Jewish rulers and Roman appointees ignored John’s legal right to be the high priest. He did not function as a visible high priest, although he held the keys, was of the proper lineage and was the Lord’s designate.
16. John was selected to restore the Aaronic Priesthood in the fulness of times because he is the greatest representative of the Aaronic Priesthood by lineage, calling, and performance, and was the last one to hold those keys.
17. With fulfillment of the law of Moses, the hereditary requirement was temporarily set aside, until the Fulness of Times.
18. The Office of Presiding Bishop belongs to the sons of Aaron. Until such is designated, a high priest of the Melchizedek priesthood can serve, if called and appointed by the First Presidency, and ordained, and sustained.
19. The Sons of Levi have an everlasting role (See Ex. 30:30-31; 40:14-16; Malachi 3:1-4; T. 319; D&C 13; D&C 128:24).
20. There will be need for the work of the Aaronic Priesthood in consecration and stewardship, even during the Millennium and afterward.
21. The Office of Presiding Bishop will someday be filled by a direct descendant of Aaron (and probably therefore be a descendant of John the Baptist).
22. Lineal sons of Levi must be of proper lineage, be designated by revelation to the First Presidency, called, ordained, and sustained, "as was Aaron."
23. The Levites are yet to offer an offering in righteousness. These will be various kinds of offerings."
Robert J. Matthews (D&C 124:39; 128:24)

The following chart was found on Ron Anderson's home page, Religion Professor at BYU - Idaho.
Link

PRIESTHOOD RESTORATION SEQUENCE
TOPIC DATE REFERENCE Aaronic Priesthood 15 May 1829 D&C 13 Melchizedek Priesthood May or June 1829 D&C 128:20 Elders Priests Teachers Deacons April 1830 D&C 20 Bishop 4 February 1831 D&C 41 High Priests June 1831 Heading to D&C 52 First Presidency 1832 D&C 81 Oath & Covenant of the Priesthood 22 Sept. 1832 D&C 84 Patriarch 1833 No Scripture Reference High Council 17 Feb. 1833 D&C 102 Quorum of the Twelve Feb. 1835 D&C 107 Quorum of the Seventy Feb. 1835 D&C 107 Keys of the Gathering 3 April 1836 D&C 110 Keys of Sealing 3 April 1836 D&C 110 Key Notes: The sequence of the restoration of the Priesthood keys and powers followed a natural sequence of growth of those ready to receive it. Most especially, Joseph Smith experiencing the most growth. Others followed his lead. "Understanding the why of the gospel and the why of the priesthood will help us to see the divine purpose of all of this. It will give us motivation and strength to do the right things, even when they are hard. Staying focused on the basic principles of gospel living will bless us with clarity, wisdom, and direction." (Dieter F. Uchtdorf, "The Why of Priesthood Service," Ensign May 2012 and April Conference 2012).