It is “the Book of Mormon term for the Melchizedek Priesthood, known to the ancients as the ‘Holy Priesthood, after the Order of the Son of God’ (D&C 107:2–4). This, ‘the holiest order,’ is the authority by which the gospel is administered in all dispensations (D&C 84:18–20). Accordingly, those called into the holy order of God had both the authority and responsibility to preach the word of God and perform ordinances … .
“President Ezra Taft Benson explained that to receive the highest blessings of the holy order is ‘the equivalent today of entering into the fulness of the Melchizedek Priesthood, which is only received in the house of the Lord’ [‘What I Hope You Will Teach Your Children about the Temple,’ 8]” (Largey, Book of Mormon Reference Companion, 334–35) .