The Melchizedek Priesthood
The Melchizedek Priesthood is one of the “orders” of priesthood in the Mormon Church. Its proper name is the “high priesthood of the holy order of God” but it is called the “high priesthood” or “Melchizedek priesthood” to avoid overusing God’s name.
In the Mormon Church, the Melchizedek Priesthood is usually given to worthy members 18 years and older who have been members of the church for over one year. Ordination is based on the person’s age, gender, and moral worthiness without regard to training, knowledge, or aptitude.
There are five offices in the Melchizedek Priesthood, in increasing authority these offices are; Elder, High Priest, Patriarch, Seventy and Apostle. An Elder is a man at least 18 years old. In the office of an Elder a man has the power to confer the Gift of the Holy Ghost, ordain other Elders and bless the sick by the laying on of hands. They also have the authority and responsibilities of all the duties of a Priest in the Aaronic Priesthood. A High Priest is a man 18 years or older who serves in a leadership position such as a Bishop. High Priests are able to ordain other High Priests and hold all the duties of an Elder. A Patriarch can be a man 18 years or older, but most Patriarchs are much older men. A Patriarch is ordained in every area of the Church to give Patriarchal Blessings to members within his stake. A Seventy is a male adult 18 years or older. They assist the Apostles, and serve as General or Area Authorities. Seventies may also have other ‘special assignments’ as directed by the First Presidency. When a Seventy becomes 70 years old, he is typically granted ‘emeritus status’ and retires from his special assignments and assumes the role of a High Priest (although he still officially holds the office of a Seventy.)
An Apostle is the highest office in the Melchizedek Priesthood and in the LDS Church. Apostles are usually chosen from existing Seventies. They are ‘Special Witnesses’ of Jesus Christ who hold all the keys of the kingdom to officiate in all responsibilities, and duties of the Priesthood. Some of those duties include having the sealing power and the power to act as a Prophet, Seer, and Revelator.
 Alma 4:20, 13:8