I want to consider a broad overview of Hebrews through the title “Son” that opens the book (Heb. 1:2).
“Son of God” in Biblical-Theological Overview
Adam was the first son of God (Gen. 1:27-28, Lk. 3:38). Seth and his descendents were sons of God (Gen. 5:1-3ff, cf. Gen. 6:2). Being the son of God has to do with ruling and guarding God’s creation. After the Fall, the sons of God are the line of promise, the “seed” of the woman promised who would crush the “seed” of the dragon (Gen. 3:15). While Noah is a new Adam (Gen. 9), this theme picks up with the patriarchs and the need for Abraham to have a son. After Isaac, the theme of the “firstborn” comes to the fore with Esau and Jacob. The firstborn receives a double portion (the birth right) inheritance in order to care for his father’s family and take over the household when the father is gone. Israel is explicitly called the firstborn son of God (Ex. 4:22), and this “firstborn” theme picks up in the Passover narrative (13:1-2) and God later explains that in place of all the firstborn of Israel, the Levites have been chosen (Num. 8:14-18). Of course the Levites “have no inheritance,” because their inheritance is in the house of God (Num. 18:21ff). This gives us a picture of the calling of the “son of God” to be a ruler over the household of God, but this rule is displayed in the sacrificial ministry of the tabernacle where “sons of the herd” are offered (Lev. 1:5, 14, 4:3, 14, 5:7, et passim). The “son of God” is to rule the world from the house of God through the blood of self-sacrifice. This begins to get at the calling of Israel to be a “kingdom of priests” (Ex. 19:5-6). The “son of God” theme picks up again in the Davidic covenant applied to Solomon (2 Samuel 7:12-16) and is also found in Ps. 89:20, 24-27 applied to David himself. There is finally an emerging angelic element to the title “son of God” particularly in Job (1:6, 2:1, 38:7) and perhaps also in Daniel (Dan. 3:25). This suggests an eschatological or glorified trajectory to mission of the son of God. This is perhaps the prophetic aspect of that title as well. A helpful summary of the calling of the son of God seems to be found in Ps. 110:1-4 where kingly and priestly duties are found in the same person just like they were found in Melchizedek. Yet, what remained for Melchizedek and all of those who approached this mission (e.g. Samuel, David, and Solomon), was the glorified, eschatological, and resurrection reality which is dimly pictured in the ministry of angels (Mt. 22:30). The problem with all the previous “sons of God” is that they don’t have the ability to be the self-sacrificing Priest-King and come back unscathed. They all fail and eventually die.
So What About Hebrews?
In the first few verses it seems obvious that the writer is working with all of this Old Testament theology in view. The Son is greater than the angels (1:5-14), and all things have been put in subjection under him (2:8). Furthermore, this Son has been made like all the other “sons” in order to bring those “sons to glory” (2:10-18). This Son of God is (not surprisingly) a High Priest who has been given his Father’s house (3:1-6). Sabbath and rest has everything to do with building the house of God and giving rest to the land (Dt. 25:19, Jos. 21:44, 2 Sam. 7:1, 1 Chr. 22:9), and it all reminds us of Noah who was a new Adam, the son of God. Jesus is the new Noah/Joshua/David/Solomon who has given rest to the people of God (Heb. 3:7-4:13). But High Priests do not simply appoint themselves; not just anyone can be the firstborn Son of God. He must be appointed (Heb. 5:4). So Christ was appointed High Priest through being a Son (5:8), but he was perfected and learned obedience through his suffering, death, and resurrection and became like Melchizedek (5:8-10). The Son without genealogy, without beginning or end is a superior Son to Abraham and the sons of Levi who paid him tithes (7:1ff). Of course Jesus is from Judah, and the only way a priest could come from a different tribe is if he were something better than any human priest has ever been, someone with the “power of an endless life,” someone who “always lives” (7:16-17, 20-25). This is a completely new kind of covenant because this High Priest serves in the “true tabernacle” in the heavens (8:1-2). And the writer recognizes that it is the Son’s duty to build the house of God and carry on its mission in the world (9:1-10) which is the redemption of the world, and Jesus has done this in that He is the true Son who offers Himself which is far greater than the “sons of the herd,” those bulls and goats which could not take away sins (10:4). He is the true King who rules by laying his own life down. The “sons of the herd” did not continue to intercede for sins, and their blood was shed continually proving that they were not sufficient (10:5-18). But we have a High Priest over the house of God whose blood is a new a living way into the Most Holy Place (10:19-23).
The Son who Makes Sons
Hebrews opens suggesting that the Sonship of Jesus is directly related to what God intends for humanity (2:11-12, 16-17, 3:1), and this is affected by the obedience and suffering and perfecting of the Son, who has become the author of eternal salvation to all who obey Him (5:9). To be a son with the Son is to be His brother and to be promised a Priestly-Kingly inheritance with Him. This means that we are called to imitate those brothers/sons that have gone before us in faith (Heb. 11), and we must expect to be treated as sons by our Father (12:5-11). We must not imitate the evil sons of the past like Esau who sold his birthright and inheritance (12:16). We are called to live in the reality of God’s fire-presence in our midst. We are the sons of God in the Son, and we have been brought to the new house of God, “the church of the firstborn,” the new tabernacle, and God’s Spirit-Fire presence is sanctifying us (12:18-29) and this means living like sons of the house of God and carrying on the order and mission of the house (Heb. 13:1-17).