The Melchizedek priesthood is the 2 witnesses. This came out in a podcast on 2 16 2012 on the 2 witnesses being the Royal Priesthood Overcoming false doctrine from our time in the corporate church system take time. The significance of this priesthood is lost within the labyrinth of doctrine.

The Mechizedek Royal Priesthood ministers in the Latter House

The 2 witnesses are typed as Zerubabbel the Governor of Judah Royal lineage of the line of David, there’s the kingship and Joshua the High Priest at the time of the end of the babylonian captivity. They were instruments that the Lord used in rebuilding the temple.
That is the type and shadow of the 2 witness royal priesthood that leads the latter day remnant out of mystery babylon (deception)
The Melchizedek Priesthood receives the glory. They are the latter house.

1Pe 2:5 Ye also, as lively stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ.

Hag 2:2 Speak now to Zerubbabel the son of Shealtiel, governor of Judah, and to Joshua the son of Josedech, the high priest, and to the residue of the people, saying,

Hag 2:9 The glory of this latter house shall be greater than of the former, saith the LORD of hosts: and in this place will I give peace, saith the LORD of hosts.

Jer 23:5 Behold, the days come, saith the LORD, that I will raise unto David a righteous Branch, and a King shall reign and prosper, and shall execute judgment and justice in the earth.
Jer 23:6 In his days Judah shall be saved, and Israel shall dwell safely: and this is his name whereby he shall be called, THE LORD OUR RIGHTEOUSNESS.
Jer 23:7 Therefore, behold, the days come, saith the LORD, that they shall no more say, The LORD liveth, which brought up the children of Israel out of the land of Egypt;
Jer 23:8 But, The LORD liveth, which brought up and which led the seed of the house of Israel out of the north country, and from all countries whither I had driven them; and they shall dwell in their own land.