What was the purpose of the tutors that wealthy Romans and Greeks hired?
Wealthy Romans and Greeks hired tutors to prepare a child who was a legal son and heir. Until the child completed his tutoring, he had no more authority in the family than a slave, even though he was blood heir and lord of all.
Les explains that Paul dips into the Greek and Roman culture, not the Jewish background, for this illustration. The wealthy Romans and Greeks would hire tutors, and the sole purpose of these tutors was to prepare that child—the legal son who was an heir. As long as he remained a child, he differed nothing from a servant or slave, even though he was lord of all. He was a blood heir of the father, but until he finished his time of tutoring, he had no more authority in the family than a slave.
Now I say, That the heir, as long as he is a child, differeth nothing from a servant, though he be lord of all;