We have named a portion of the priesthood after Melchizedek. (It is not, however, the form which Melchizedek held. That is another topic I am not going to address here now. This area is complete mush in the minds of Latter-day Saint writers and commentaries. I might take it up in a book and go through it methodically there.) What is important is that the great events of Melchizedek's time began when people humbled themselves and accepted the teachings of this "high priesthood" holder and were, thereby, saved. Not only saved but also led into a fellowship which eventually turned into a City of Peace, or City of Salem, or Jerusalem, which was taken into heaven.
This prototype was so influential in the thinking of all who followed, that the high priesthood was named after Melchizedek. Even though he held Patriarchal Priesthood with its associated sealing power, he was the one after whom Melchizedek Priesthood was named in the form it was later transmitted which lacked sealing authority. (Again, another topic.) What is important in this verse is the connection between the existence of the one holding this authority (Melchizedek), and a humble people who would accept and follow those teachings. The result of the combination of the two was that God came and dwelt among them. This is a pattern that followed the previous pattern with Enoch. This was the pattern Joseph wanted to return through his teaching and ministry. Joseph wasn't able to accomplish it. We now hope to see it someday occur in the unfolding history of The Church of Jesus Christ of Latter-day Saints. The most recent book on this subject, now on sale at Deseret Book (unfortunately a red-flag for me) urges the idea that the only Zion we should expect to see will come when the church president allows or directs it to happen.
This verse suggests what is needed is: 1) humble people willing to accept teaching from a high priest after the ancient order and 2) a person having that authority who will teach.