That the Son was born under the law means
he was Jewish and lived in subjection to the Mosaic law; or
he was fully human.
We can deduce what Paul means that the Son was born under the law by reading also Galatians 4:5. There Paul explains that Jesus was born under the law to redeem those under the law. We know that unless the Israelites were able to uphold all the requirements of the law, they would be under a curse (Galatians 3:10). We also know that the law imprisoned Israel (Galatians 3:23), so clearly they could not uphold the law. What Jesus did was redeem Israel by taking the curse of the law upon himself (Galatians 3:13), and he did this by being born under the regulations of the law. Thus, when Paul says that the Son was born under the law, he means that he was born under the same regulations of the Mosaic law as the Israelites.
Some argue that when Paul says the Son was born under the law, his point is that he was a human. The notion is that Paul simply repeats himself in Galatians 4:4. He says that the Son was born of a woman, which means he partook of the human condition, and was born under law, which confirms the same. The argument is that since all humans are born under the law, Jesus, as one who partook of the human condition, was also born under the law.
This view does not get to the heart of Paul’s thought throughout this section of Galatians. While it is important that Jesus was born a human, it was also important that Jesus was born under the same regulations as Israel, and yet, he obeyed God’s law fully. In fact, it was common for Jewish authors to characterize the ordinances of the law as being under the will of God. And we know that Jesus came to obey the Father’s will. Finally, it is unlikely that Paul would repeat himself to show that Jesus participated in the human condition, because Paul makes this point clear by saying that the Son was born of a woman. He does not need to repeat this point, but he does explain that the Son was born under the regulations of the Mosaic law.
When Paul says that God sent his Son, born of a woman, born under the law, his point is that the Son was born under the regulations of the Mosaic law, which reflect God’s will. And because the Son obeyed that law perfectly, he is crowned with an eternal inheritance that he shares with all those who place their faith in him.
Interpretation 1:
Christ was Jewish and lived in subjection to the Mosaic law.
Summary:
The Israelites were under God’s curse because they could not uphold the Mosaic law. To redeem them God sent his Son into the world, born as a human, and subject to the regulations of the law.
Jesus Christ obeyed God’s will fully, and by doing so, became the recipient of an eternal inheritance. Christ so loves us that, even though we fall short of God’s will, he shares his eternal inheritance with all those who put their faith in him.
Advocates:
James Dunn
Richard Longenecker
Douglas Moo
Minor differences:
There are no substantial differences between our authors. All agree that the notion that the Son was born under the law means that he was subject to the Mosaic law. Moo paraphrases the notion that the Son was born under law with the phrase subject to the rule of the law.
1 James Dunn says that Jesus shared in Israel’s subjection to the law,2 and Longenecker writes that Jesus was under obligation to God’s Torah.
3
Arguments
Possible weaknesses
Interpretation 2:
That the Son was born under the law means that he was fully human.
Summary:
Paul wants the Galatians to know that the Son was fully human. Paul makes this point by stating that he was born of a woman, and he was under the law.
Advocates:
Ronald Fung
Frank Matera
Thomas Schreiner
Minor differences:
Our authors agree that when Paul says that the Son was born under the law, his point is that Jesus was fully human. Frank Matera summarizes the position when he writes, Its use here indicates that God’s Son experienced the fullness of the human condition.
At the same time, Matera says that the phrase under the law
points to Jesus’ Jewish heritage.9 So it is not clear whether Matera thinks the phrase is about Jesus’ humanity or his Jewishness.
For Ronald Fung and Thomas Schreiner, the phrase is about Jesus’ humanity. That is because in their view, to be born a human is to be born under the law. Thus, the phrase is not particularly about Jesus' Jewishness, but about his human condition.10,11
Arguments
Possible weaknesses
4 But when the fullness of time had come, God sent forth his Son, born of woman, born under the law,