Hebrews 8

Chapter 7 of Hebrews was a long argument comparing Melchizedek & Jesus and contrasting that priesthood with the Aaronic/Levitical priesthood. It was a very logical argument full of Old Testament observations. Now, in chapter 8, the author of Hebrews gets practical and states his main theme with a passion

Hebrews 8:1-2
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, and who serves in the sanctuary, the true tabernacle set up by the Lord, not by man.

'Such' a 'High Priest' refers us back to the phrase in 7:26. Jesus is the type of High Priest that 'meets our need'. Unlike the earthly priests, Jesus sits beside the throne in heaven and serves in the true tabernacle. In what capacity does he serve? The author tells us in 9:24-26 that His work there is 'to appear for us in God's presence...once and for all'.

He then shows the shadows and the better reality

Shadows: High Priests offer gifts/sacrifices
Reality: Jesus offers a once and for all gift/sacrifice

Shadows: Earthly Priests
Reality: Heavenly Priest

Shadow: Earthly Sanctuary
Reality: Heavenly Tabernacle

Shadow: Old Covenant
Reality: New Covenant

Regarding this New and Superior Covenant, the author quotes Jer. 31:31-34

Ways in which the New Covenant is better than the Old Covenant:
1. Instead of the laws being written on tablets, the law would now be written on the hearts and minds of the people.
2. Instead of only the priests experience the presence of God, all men will have such access
3. Instead of the never-ending sacrifices, now there is a once and for all sacrifice

The author concludes by making the following remark:

Hebrews 8:13
By calling this covenant "new," he has made the first one obsolete; and what is obsolete and aging will soon disappear.

Thus, a new covenant overrides a previous covenant. And the previous covenant, now obsolete (being merely shadows of reality) was about to disappear. This, in fact, happened as the temple in Jerusalem was destroyed in AD70.