The writer began by proving that Jesus is superior to the angels in chapters 1-2, and not who will show that Jesus is superior to Moses. Why move from angels to Moses? For most modern readers, angels are superior to humans, so if Jesus is superior to angels, he would obviously be superior to Moses as well.
But it is important to read this argument in the context of first century Jewish Christianity. For Jews living in the Second Temple period, Moses was the most significant person in salvation history. In Sirach (about 200 B.C.), Moses is described as equal to the “holy ones” or even God himself (as the Hebrew text of Sirach can be translated):
Sirach 45:1-2 …and was beloved by God and people, Moses, whose memory is blessed. He made him equal in glory to the holy ones, and made him great, to the terror of his enemies.
In addition, messianic hopes in the first century sometimes focused on the coming of a prophet like Moses. Hope for a “return of Moses” as messiah was so strong that at least one messianic pretender stopped the Jordan in a re-enactment of the crossing of the Red Sea. Matthew’s gospel is designed to highlight Jesus as a new Moses who goes up on the mountain and gives the people the Law–the Sermon on the Mount!
One might have offered a counter argument to the first two chapters of Hebrews: Jesus might be superior to the angels, but the ultimate servant of God was Moses, who gave the Law. In the context of the first century, then, our author will argue that Jesus is a superior to even Moses as a servant of God. Ultimately, this will lead to the conclusion that the covenant which Jesus made (the New Covenant) is superior to that of the Old Covenant made by Moses. In verse two Moses is compared to Jesus, then he is subordinated to Jesus (verse 3) and by verse 5 he is contrasted to Jesus, negatively.
The author of Hebrews makes a “lesser to greater” type of argument. If Moses was faithful in God’s household in the previous age, how is Jesus be superior to him in the present age? First, Jesus is superior because he is the builder of the house. Here the writer is making the point that Jesus is God, and because God is the designer of the administration that Moses presided over, he is therefore superior to him.
Second, Moses is a servant of the house, but Jesus is the son of the Builder, and therefore heir to the administration himself. He is of a different class that Moses, beyond servant. This takes into consideration the first argument of the book, that the angels were servants, but Jesus is the son. Moses is a servant, but the word here is unique in the New Testament to Moses. It is not a slave, but an “attendant,” one who “renders devoted service” (BDAG). The LXX uses the word for Moses in Num 12:7 (as well as Exod 4:10 and 14:31).
Moses was a servant of the first class, but he is still a servant of Jesus, and therefore subordinate to him. What else in Hebrews 3 shows Jesus as superior to Moses?