It is written,
“Others became priests without any oath, but He [Jesus] became a Priest with an oath when God said to Him, ‘The Lord has sworn and will not change His mind: You are a Priest forever.’” Hebrews 7:21
It is repeated In Hebrews 5:6,10; 6:20; 7:11 that God said to Jesus,
‘You are a Priest forever in the order of Melchizedek.’
The reference that Jesus would be a Priest in the order of Melchizedek is found in Psalm 110:4 Note the emphasis,
“The Lord has sworn and will not change His mind, ‘You are a priest forever in the order of Melchizedek.’”
We learn about Melchizedek in Genesis 14:18-20
Jesus is our High Priest,
‘The point of what we are saying is this: We do have such a High Priest who sat down at the right hand of the throne of the Majesty in heaven…’ Hebrews 8:1
The role of the high priest and his appointment by God is found in various sections of the Pentateuch in the Old Testament. We can more fully understand the wonderful High Priest, Jesus, by studying these portions of the Bible.
The question, does God expect us to know the Old Testament, is clear: He does.
That is why we have the Old Testament and the New Testament. Both have as main focus, Jesus, our glorious Saviour and Lord. With the help of the Holy Spirit we can appreciate our Bridegroom so much better.