The next time we see the son of God in the Old Testament is in the story of Moses, the people of Israel¹ and Pharaoh. The people of Israel had been in bondage as slaves to the Egyptians for over 400 years. They cried out to God and he sent them Moses to deliver them.
When God called Moses to be a prophet who would deliver his people he said to him, “When you go back to Egypt, see that you do before Pharaoh all the miracles that I have put in your power. But I will harden his heart, so that he will not let the people go. Then you shall say to Pharaoh, ‘Thus says the Lord, Israel is my firstborn son, and I say to you, “Let my son go that he may serve me.” If you refuse to let him go, behold, I will kill your firstborn son’” (Exodus 4:21-23).
In this text God makes the remarkable statement that Israel is his son, and not just any son, but his firstborn son. The firstborn son was the one who had the most honor. Douglas Stuart helps us see the significance and honor of being the firstborn, “The firstborn son in the ancient world was the one specially favored with inheritance, the one who would represent the father in many ways as he came into maturity and the father gave him more and more responsibility. Moreover, in ancient Israelite society the firstborn son, as the firstfruits of a marriage, was devoted to God-he belonged specially to God. . .”²
Israel was God’s firstborn son, not because they were better than the other peoples around them (they weren’t, see Deuteronomy 7:6-9), but because God graciously chose them out of all the peoples on the earth when he made his covenant with Abraham (see Genesis 12:1-3). As God’s firstborn son they enjoyed special privileges and had unique responsibilities (It was the failure to live up to these responsibilities that led to them not enjoying the special privileges).
We see the sonship of Israel repeated again in Jeremiah 31:9, “With weeping they shall come, and with pleas for mercy I will lead them back, I will make them walk by brooks of water, in a straight path in which they shall not stumble, for I am a father to Israel, and Ephraim³ is my firstborn.”
Israel was God’s uniquely chosen people whom he adopted as a son. Israel was the son of God.
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1 I do not believe that the people of Israel in the Old Testament is directly equivalent to the State of Israel today. Obviously, this is also a contentious issue, but not one that we will go into now. For this series, whenever I speak of Israel I am always talking about the people of Israel during the time of the Old Testament and am never talking about the modern day nation state of Israel.
2 Douglas Stuart, Exodus, The New American Commentary (Nashville: Broadman Holman, 2006), 146.
3 Ephraim was one of the 12 tribes of Israel and often is spoken of as the representative of all Israel, as it is here.
Part 1: Adam Is the Son of God
Part 2: The People of God Are the Son of God
Part 3: The Son of David is the Son of God
Part 4: Jesus Christ Is the Son of God
Part 5: Jesus Christ Is God’s Unique Son
Part 6: Believers Are Sons and Daughters of God

This is a great discussion, Dustin. I so appreciate your clear and fair communication. I’m looking forward to more “contentious issue” posts – from you and others.
[...] 1: Adam Is the Son of God Part 2: The People of God (Israel) Are the Son of God Part 3: The Son of David Is the Son of God Part 4: Jesus Christ Is the Son of God Part 5: Jesus [...]