I mean that the heir, as long as he is a child, is no different from a slave, though he is the owner of everything, but he is under guardians and managers until the date set by his father. In the same way we also, when we were children, were enslaved to the elementary principles of the world. But when the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons. And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!” So you are no longer a slave, but a son, and if a son, then an heir through God.
Formerly, when you did not know God, you were enslaved to those that by nature are not gods. But now that you have come to know God, or rather to be known by God, how can you turn back again to the weak and worthless elementary principles of the world, whose slaves you want to be once more? You observe days and months and seasons and years! I am afraid I may have labored over you in vain. (ESV)