WHY WE CELEBRATE CHRISTMAS (INCARNATION)
1 God, after He spoke long ago to the fathers in the prophets in many portions and in many ways,
2 in these last days has spoken to us in His Son, whom He appointed heir of all things, through whom also He made the world.
3 And He is the radiance of His glory and the exact representation of His nature, and upholds all things by the word of His power. When He had made purification of sins, He sat down at the right hand of the Majesty on high,
4 having become as much better than the angels, as He has inherited a more excellent name than they. (Heb 1:1-4 NASB)
The Book of Hebrews is one long, sustained defense of God becoming flesh for the purpose of being our sacrifice and our high priest. It is important to carefully look at certain words in the first three verses because the identity of the Son is found in them. The word for radiance is ἀπαύγασμα “apaugasma.” The word means effulgence, or radiance. He is the radiance of His glory. The early church understood that this means the Son is the light of very light. He is of the same light as the Father, He is, in essence, the light of very light.
“The exact representation of His nature” (Heb 1:3 NAU) The Greek is καὶ χαρακτὴρ τῆς ὑποστάσεως αὐτοῦ (Heb 1:3 BGT). The two words of focus here is χαρακτήρ (charakter) and ὑπόστασις hupostasis. The idea of exact representation is related to coins and seals. Coins and seals were the exact copies imprinted by a die. What is it here that the Son is an exact copy of? It is the hupostasis, the very nature of God. Anyone familiar with the ecumenical creeds will recognize where the creedal language came from. It was not from Greek philosophy but from the Jewish intellectual tradition based on the Old Testament.
The Son is the very light of light. He is the exact image of the nature of the Father, He is of the same substance with the Father. Furthermore, we learn that all things are created through the Son. We learn that the Son sits at the right hand of the Father. The Father even calls Him God. We learn that the angels worship him. We learn that His enemies will become his footstool. We will learn later in the book that the Son stands before the Father as our High Priest. Having offered himself as a substitutionary sacrifice, He now stands before the Father as our Advocate, our Intercessor.
Hebrews teaches us that the Father and the Son are of the same nature, one in nature but are two persons who stand beside each other. The same argument can be made for the Holy Spirit as well. The doctrine of the trinity is biblical, found in the text itself. It is an essential doctrine. And without it, there is no salvation or Christianity for that matter.