Gen 3:22 Then the LORD God said, "Behold, the man has become like one of us in knowing good and evil. Now, lest he reach out his hand and take also of the tree of life and eat, and live forever--"
Gen 3:23 therefore the LORD God sent him out from the garden of Eden to work the ground from which he was taken.
Gen 3:24 He drove out the man, and at the east of the garden of Eden he placed the cherubim and a flaming sword that turned every way to guard the way to the tree of life.
There was no longer, at that point, an easy access to God. And the aftereffects remained to that day, as our Author points out:
Heb 5:11 About this we have much to say, and it is hard to explain, since you have become dull of hearing.
Heb 5:12 For though by this time you ought to be teachers, you need someone to teach you again the basic principles of the oracles of God. You need milk, not solid food...
How do these connect? The boundary between God and man wasn't just a cherubim with a magic sword (so to speak). It was a boundary of the mind as well. Why would God reprove the Hebrews of this day, if He set the boundary? Because, as Jesus had said:
Joh 5:39 You search the Scriptures because you think that in them you have eternal life;and it is they that bear witness about me,
Joh 5:40 yet you refuse to come to me that you may have life.
The Old Testament shows Jesus in 'shadow form'; everything in them is a foreshadowing of what Jesus WOULD be. But they absorbed the structures of that shadow- the supernatural, Moses, the Law- but they never tried looking to see what CAST the shadow. And now, there was one more structure to tear down, which the author introduced last time: the High Priest.
Heb 5:1 For every high priest chosen from among men is appointed to act on behalf of men in relation to God, to offer gifts and sacrifices for sins.
Heb 5:2 He can deal gently with the ignorant and wayward, since he himself is beset with weakness.
Heb 5:3 Because of this he is obligated to offer sacrifice for his own sins just as he does for those of the people.
Heb 5:4 And no one takes this honor for himself, but only when called by God, just as Aaron was.
So let's tear this down. First, a High Priest was appointed; unlike the politics it evolved into by their day, it was neither passed down through direct blood or chosen by men- God was to choose which son of Aaron. Second, the High Priest could represent because he shared the weakness, the sin nature, of the people. Because of this, he had to offer sacrifices for HIMSELF as well; but by this point, he had become, as the Romans might say, a god among men...
Joh 18:22 When he had said these things, one of the officers standing by struck Jesus with his hand, saying, "Is that how you answer the high priest?"
This too had to be torn down, replaced by the TRUE High Priest. First, the author re-establishes the first connection he uses between God and Christ...
Heb 5:5 So also Christ did not exalt himself to be made a high priest, but was appointed by him who said to him, "You are my Son, today I have begotten you";
And introduce them to a new concept he will build on: the idea of a priesthood beyond the Levitical:
Heb 5:6 as he says also in another place, "You are a priest forever, after the order of Melchizedek."
In v5, he also establishes the first requirement of High Priesthood: Jesus was appointed by God. Remember, the leaders of the Jews had accused Him of appointing Himself:
Joh 19:7 The Jews answered him, "We have a law, and according to that law he ought to die because he has made himself the Son of God."
But here the author dismisses that claim. Next, though, comes a statement that might seem puzzling to us:
Heb 5:7 In the days of his flesh, Jesus offered up prayers and supplications, with loud cries and tears, to him who was able to save him from death, and he was heard because of his reverence.
Heb 5:8 Although he was a son, he learned obedience through what he suffered.
Did Christ have to LEARN obedience? No, but in His flesh He had to PROVE that obedience- unto death on the Cross. This separated him from the fleshly High Priests: He didn't have a weakness, He didn't have to make sacrifices for HIS sins, and making Himself the sacrifice for the people perfected Him, in God's eyes...
Heb 5:9 And being made perfect, he became the source of eternal salvation to all who obey him,
Heb 5:10 being designated by God a high priest after the order of Melchizedek.
One sacrifice for all. But Melchizedek again? This is all set up to the next few chapters, but the point is that He is of a higher priesthood than that of Aaron. Remember, a priest had to be of Levi, but Jesus was "of Judah". Therefore, there needed to be a priesthood that went back before the sons of Jacob. And there was- and that's where the author is going. And because the Jews should have seen that- in its foreshadowing- he calls them 'dull of hearing.'
So now, the idol of the "Office of High Priest" has been torn down. So many trees that had been erected between man and God. Anything that could possibly been put in the way of that direct contact with God- like a 'flaming sword that turned every way'. The author was about to explain how the way back to God had been restored.
