Galatians 4:1,2

Each society has a time for a young boy to become a man. In Paul’s days, it was a very important event. As soon as a boy became a man, he had full legal rights. Until that time, other people had to manage a child’s personal and business affairs. Young children could not own property, even if their father gave it to them. Young children had no rights. Slaves could not own property either. Slaves had no rights. So young children and slaves were in the same situation. In *Jewish society, a boy became a man soon after he was 12 years of age. In *Greek society, a boy became a man at about 18 years of age. In *Roman society, the child’s father decided when the child was ready to be an adult. So Paul was probably using *Roman society as a model in this verse.