Thank you. Here is a quote I found interesting from the link you gave;
“St. Paul used the person of Melchizedek to illustrate the doctrine of the sacrificial priesthood as established by Christ. St. Paul begins, Every high priest is taken from among men and made their representative before God, to offer gifts and sacrifices for sins (Hebrews 5:1). Despite human weakness, a man is called by God to be a priest.”
"5 Every high priest is selected from among the people and is appointed to represent the people in matters related to God, to offer gifts and sacrifices for sins. 2 He is able to deal gently with those who are ignorant and are going astray, since he himself is subject to weakness. 3 This is why he has to offer sacrifices for his own sins, as well as for the sins of the people. 4 And no one takes this honor on himself, but he receives it when called by God, **just as Aaron was.
5 In the same way, Christ did not take on himself the glory of becoming a high priest. But God said to him,
“You are my Son;
today I have become your Father.”[a]
6 And he says in another place,
“You are a priest forever,
in the order of Melchizedek.”**
7 During the days of Jesus’ life on earth,*** he offered up prayers and petitions*** with fervent cries and tears to the one who could save him from death, and he was heard because of his reverent submission. 8 Son though he was, he l***earned obedience from what he suffered 9 and, once made perfect***, he became the source of eternal salvation for all who obey him 10 and was designated by God to be high priest in the order of Melchizedek.
Hebrews 5:5 Psalm 2:7
Hebrews 5:6 Psalm 110:4
Aaron was chosen by God but he was not of the Melchizedek order so when the great sacrifice of Christ was done then this high order of the priesthood came into effect. This is what I understand of the scriptures above. The priests today are in fact of the high order of Melchizedek. They continue to offer bread and wine as a sacrifice to the Most High for all our sins. It is in fact the Lord’s body and blood. He who does not eat of His flesh and drink of His blood cannot have everlasting life, Jn 6:53-55. Therefore am I to believe that those christian sects who do not practice this or whose priests are not directly descended from the apostles as the appointed high priests, in the order of Melchizedek, are doomed?**