Why is it important that Jesus is our High Priest? & two other notes

Hebrews

7.19  nothing made perfect...  "This is explained in the words, “for the law made nothing perfect.” The words “made perfect” are the translation of teleioo (τελειοο) which means “to carry through completely, to make complete, to finish, bring to an end.” The Mosaic economy brought nothing to a conclusion. It could not offer a sacrifice which would pay for sin. Therefore, it could not save anyone. Therefore, it was set aside."  --Wuest, K. S. (1997). Wuest's Word Studies from the Greek New Testament: For the English Reader (Heb 7:18). Grand Rapids: Eerdmans.

 7.22  surety of a better covenant...   "The term for “guarantee” (NASB, TEV) or “surety” (KJV) in verse 22 was used in business documents for a deposit, a security guaranteeing that one would carry through on one’s word or obligation, or someone who made such a guarantee."  --Keener, C. S. (1993). The IVP Bible Background Commentary: New Testament (Heb 7:22–25). Downers Grove, IL: InterVarsity Press.

Jesus: From Melchizedek to Eternal Savior

December 1, 1996 | by John Piper | Scripture: Hebrews 7:1–25 | Topic: The Person of Christ

Series: Hebrews  

This is three paragraphs about why we need a priest  from a full sermon by John Piper.
 

If, to be saved forever, we need Christ to intercede for us forever with God, then what is the implication about what we need saving from? The implication is that we need to be saved from God. Specifically we need to be saved from the wrath of God that burns against all ungodliness and unrighteousness (Romans 1:18). Christ can save us forever from the wrath of God because he intercedes forever with God. He continually puts himself between the Father and us as an asbestos shield against his white-hot anger against sin. Hebrews 10:30-31 says, "We know Him who said, 'Vengeance is mine, I will repay.' And again, 'The Lord will judge his people.' It is a terrifying thing to fall into the hands of the living God."

Until we get this firmly and clearly fixed in our minds, hardly anything in the book of Hebrews will make sense. The major problem in the world and in our lives is not our troubled marriages or our wayward children or our financial pressures or our failing health or our cultural degeneration. The main problem in the world—everybody's problem—is how to be reconciled to God so that we escape his terrifying wrath at the judgment. That's the main problem.

And the Biblical answer is priesthood. And specifically the superior priesthood of Christ. The reason there are priests in the Old Testament is that priests are needed to intercede for us with God. They enter the holy place where we are not allowed to go. And they take sacrifices for us so that our sins will be forgiven. All of that Old Testament priestly system was meant to teach us about our sin and the holiness and wrath of God and the inescapable judgment that is coming on us. And the point of it all was this: God has made a way to get right with God. He provided priests in the Old Testament, and then he provided his Son, the final High Priest.