The book of Hebrews is devoted to one common theme: the superiority of Jesus. The author covers subjects ranging from faith to animal sacrifices, and from angels to the kingdom of God, but all of that information is given to prove one essential point: that Jesus is better (1:4; 7:19,22; 8:6; 9:23; 10:34; 11:16; 11:35,40; 12:24).
Better than what? Well, the short answer to that is, everything (especially everything the Hebrews writer mentions; see below). But, the more important point is that Jesus is just plain better because of who He is—because of His nature. Hebrews declares that Jesus is both God and man, and that if He were not both He could not save anyone since He would be no better than anyone or anything else.
So, Hebrews begins with this incredible statement: “[Jesus Christ] is the radiance of the glory of God and the exact imprint of his nature, and he upholds the universe by the word of his power. After making purification for sins, he sat down at the right hand of the Majesty on high…” (Hebrews 1:3, ESV) To summarize, the writer says that Jesus is exactly like God in every way, He is divine, He is God.
That point is proven in the course of the book by declaring that Jesus is better than (among other things): Angels (ch 1); Moses, the Law-giver (ch 3); The earthly high priests (chs 4b-5); All other promises and covenants (chs 6,8,9b); Abraham (ch 7); All other sacrifices (chs 9-10); All other kingdoms (ch 12)
But, the writer of Hebrews also makes this assertion: “Since therefore the children share in flesh and blood, [Jesus Christ] himself likewise partook of the same things…” (Hebrews 2:14a, ESV) Again, to summarize, the writer is claiming that Jesus is human.
That point is proven as the writer speaks of these mortal, human aspects of Jesus and His work: Made lower than angels (ch 2); Died; Resurrected; Resisted temptation (4:15); Became High Priest (ch 5); Brought the New Covenant (Will) through His death (ch 9b); Became our perfect sacrifice (ch 10); Opened the heavenely temple with His blood (ch 9).
This leads us to the Cliff’s Notes summary of Hebrews: Jesus is strong enough to save, but weak enough to die. That is a unique combination that could only be fulfilled if Jesus is as powerful as God, but as weak as a human. He has to be God in the flesh.