Expositor's Bible Commentary Commentary Galatians 4:1

"But I say that so long as the heir is a child, he differeth nothing from a bondservant though he is lord of all;" — Galatians 4:1 (ASV)

The moment of growing up was a definite one in antiquity, and it involved matters of great religious and legal importance. For instance, in Judaism a boy passed from adolescence to manhood shortly after his twelfth birthday, at which time he became “a son of the law.” In the Greek world the minor came of age at about eighteen, but there was the same emphasis on an entering into full responsibility as an adult. Roman law also had a time for the coming of age of a son, but the age when this took place does not seem to have been firmly fixed; the father apparently had discretion in setting the time of his son’s maturity. It seems likely that Paul is referring primarily to the Roman custom as he observed a child “under guardians and trustees until the time set by his father.” At that time the child was formally adopted by the father as his acknowledged son and heir and received special adult clothes.

When the child was a minor in the eyes of the law, his status was no different from that of a slave, even though he was the future owner of a vast estate. He could make no decisions, he had no freedom. But at the time set by his father, the child entered into his responsibility and freedom. The application of the illustration is obvious as Paul applies it to the inferior condition of people under law, both minors and slaves, and to the new freedom and responsibility that come to them in Christ.