We read in Exodus 4:22 that the people Israel are God's firstborn son:
"Then you shall say to Pharaoh, 'Thus says the LORD, "Israel is My son, My firstborn. (NASB)
So now, how can Jesus be the firstborn Son of God, let alone the only Son?
Several of the "prophecies" about Jesus mentioned in the Gospels refer to what is in fact a statement about Israel the past and present. For example Matthew describes the family of Jesus leaving Egypt and says:
"He remained there until the death of Herod. This was to fulfill what had been spoken by the Lord through the prophet: "OUT OF EGYPT I CALLED MY SON."" - Matthew 2:15 (NASB)
The Prophet referred to in Mathew 2:15 is Hosea, who says:
When Israel was a youth I loved him, and out of Egypt I called My son. 2 The more they called them, the more they went from them; they kept sacrificing to the Baals and burning incense to idols." - Hosea 11:1–2 (NASB)
The problem I have with such interpretations of Jesus' actions as fulfilments of propecy are that they were 1) about Israel 2) statements about the past rather than predictions and 3) the behavior being described is hardly matching the character and actions of Jesus in the gospels.
How do Christians reconcile the logic of Jesus being God's firstborn son or even the only son, with the actual words of God in the Old Testament about the nation of Israel? I don't mean metaphorically, but what is the actual reality? How are the later verses in the Gospels interpreted? On the one hand they seem as "additional" interpretations of the "original" verses about Israel, but read "in the light of the Gospel". But that can't negate the original meaning, can it? In reality, which is it?