“…being designated by God as a high priest after the order of Melchizedek.”
Jesus is the author or source of our salvation because He is a high priest. Not just any high priest but a special high priest. Jesus is not from the tribe of Levi and therefore, cannot be a Levitical high priest. His priesthood comes not through His ancestors but through God who appointed Him high priest of His own order.
Melchizedek was a king/priest of his own order. There were no priests/kings among his ancestors, and there were no priests/kings to follow him. He stands as a king and a priest alone in his line. So Jesus is a king/priest of His own order. No high priest among His ancestors. He is king through David and God adds the role of high priest to His duties. He becomes the first and last king/priest in His line.
This fact allows Jesus to be king and high priest among the nations, not just one nation. Jesus is King of all kings, and He is the complete and final high priest of God. Even now, He rules His kingdom and intercedes for his subjects. As long as time endures so does His priesthood and with it the offer of eternal salvation.
Task for Today: Bow down to the only true king. Claim His saving grace. Be washed in His blood, buried into His death and then rise with Him into a new life. Wow! What a savior.