Who is God?
This dual title, 'Lord and Messiah', gives a clue as to how the Hebrew scriptures were understood. In their Greek translation, the covenant name of God, Yahweh (Exod 3) is translated 'Kyrios'. For example, in Psalm 110:1, the Hebrew text says 'YHWH says to Adon, sit at my right hand...'. The two characters in the dialogue are distinguished by two different titles. The Greek translation of Psalm 110:1, however, from which Peter quoted in Acts 2:34 reads: 'the Lord says to my Lord...'. Our English versions reflect the fact that the same noun is used for both persons. The distinction that was clear in the Hebrew text became ambiguous in the Greek text.
What distinguishes the Father and the Son is not a difference in divine essence, but a difference in their persons and it belongs to the person of the Son to become incarnate, but the incarnate Son is and remains consubstantial with the Father.
God the Son did not first appear in the history of redemption in the incarnation, but has been mediating the knowledge of God and saving his people for millennia before. This is how the Apostle Paul read the history of salvation and why he declared: 'There is one Mediator between God and men, the man Christ Jesus' (1Tim 2:5). We see this way of thinking in his admonition to the Corinthians regarding their conduct at the Lord's Table, where he reminded them that they were not the first to be baptised (1Cor 10:1f) and they were not the first to eat the Lord's Supper (1Cor 10:3). Indeed, they ate the same food and drank the same drink we do: 'For they drank from the spiritual Rock that followed them, and that Rock was Christ'. Paul did not see only occasional types of Christ in the Hebrew Scriptures. Rather, he saw God the Son actively operating throughout Scripture. In other words, the unity of the covenant of grace is not merely typological but substantial.
Christians today are partakers of the same justifying and saving grace by which God the Son justified and redeemed his people before the incarnation. Paul said this much when he told the Corinthians: 'For the Son of God Jesus the Messiah whom we preached among you...is not Yes and No, but in him the Yes has come. For however many are the promises of God, their Yes is in him. Wherefore also through him is our Amen to God for his glory' (2Cor 1:19-20).
'You were redeemed...with the precious blood of Christ, a lamb without blemish or defect. He was chosen before the creation of the world, but was revealed in these last times for your sake' (1Pt 1:19f).