The Bible mentions the order of Aaron and the order of Melchizedek, and the order here means lineage. In the temple on earth, the Levites were charged with offering sacrifices to God according to the Old Testament law. Among them, Aaron and his immediate descendants offered sacrifices to God in the sanctuary (temple and most holy place).

[Numbers 18:6~7] I myself have selected your fellow Levites from among the Israelites as a gift to you, dedicated to the LORD to do the work at the Tent of Meeting. But only you and your sons may serve as priests in connection with everything at the altar and inside the curtain. I am giving you the service of the priesthood as a gift. Anyone else who comes near the sanctuary must be put to death."

Aaron's order (line) refers to the office of a priest serving in the sanctuary (temple, most holy place), and this is not something that all Levites can do, only Aaron and his immediate descendants. Therefore, even if they belong to the tribe of Levi, they cannot be priests or high priests in the sanctuary unless they are of Aaron's blood. This is called the order of Aaron.

However, the Bible prophesies that priests who follow the order (prophecy, genealogy) of Melchizedek will appear, and the Bible testifies as follows.

[Psalms 110:1~5] The LORD says to my Lord: "Sit at my right hand until I make your enemies a footstool for your feet." ....(4) The LORD has sworn and will not change his mind: "You are a priest forever, in the order of Melchizedek." The Lord is at your right hand; he will crush kings on the day of his wrath.

Then, who is the priest who appears according to the order (line) of Melchizedek? Melchizedek, king of Salem mentioned in Genesis, was God's priest who blessed Abraham. However, this does not end with the history of the Old Testament alone, but it shows Yehoshua who will appear as the reality of the order of Melchizedek.

[Luke 20:41~44] Jesus said to them, "Why do they say that the Christ is the Son of David?" The LORD said to my Lord, "I will make your enemies your footstool." David called him "Lord." Call him, and how can he be his son?"

To the Sadducees who were testing him, Yehoshua quoted Psalm 110 to testify that he was the Christ who appeared in the order of Melchizedek. Therefore, the Christ who will appear in the order of Melchizedek is Yehoshua, and Isaiah testifies of Yehoshua as follows.

[Isaiah 61:1~3] The Spirit of the Sovereign LORD is on me, because the LORD has anointed me to preach good news to the poor. He has sent me to bind up the brokenhearted, to proclaim freedom for the captives and release from darkness for the prisoners, to proclaim the year of the LORD's favor and the day of vengeance of our God, to comfort all who mourn, and provide for those who grieve in Zion— to bestow on them a crown of beauty instead of ashes, the oil of gladness instead of mourning, and a garment of praise instead of a spirit of despair. They will be called oaks of righteousness, a planting of the LORD for the display of his splendor.

Isaiah prophesied that the Spirit of God would come upon the body of Yehoshua. Therefore, the Melchizedek order (blood, prophecy) that the Bible testifies to refers to people who have received the Holy Spirit, and only these people can offer spiritual sacrifices in God's temple. So how do you become a priest in the Spirit-led Melchizedek order?

[Isaiah 59:20~21] "The Redeemer will come to Zion, to those in Jacob who repent of their sins," declares the LORD. "As for me, this is my covenant with them," says the LORD. "My Spirit, who is on you, and my words that I have put in your mouth will not depart from your mouth, or from the mouths of your children, or from the mouths of their descendants from this time on and forever," says the LORD.

To become a priest according to the order of Melchizedek, you must repent. All who repent and receive the Holy Spirit will become descendants of Yehoshua who appeared as Melchizedek and become priests serving in God's temple. Just as Aaron and his immediate descendants became priests in the earthly temple, only those who have received the Holy Spirit become mediators between God and the people in the heavenly temple.

Therefore, the order of Aaron refers to Aaron and his descendants who sacrificed to God in the temple on earth, and the order of Melchizedek refers to the saints who have been regenerated by the Holy Spirit of Yehoshua, the heavenly temple.

It is not the order of Melchizedek that offers sacrifices for the forgiveness of sins in the temple built as a building. The temple of God testified in the Bible is the saints who have received the Holy Spirit, and these are the descendants of Melchizedek.