estate. The heir is subject to guardians and trustees until the time set by his father. So also,
when we were underage, we were in slavery under the elemental spiritual forces of the
world. But when the set time had fully come, God sent his Son, born of a woman, born
under the law, to redeem those under the law, that we might receive adoption to sonship.
Because you are his sons, God sent the Spirit of his Son into our hearts, the Spirit who calls
out, “Abba, Father.” So you are no longer a slave, but God’s child; and since you are his
child, God has made you also an heir.’
Here he defines for us perfectly what it means to be God’s sons and children in the
flesh, by creation and by birth to human parents, and what it means to be God’s
children by divine promise, in a spiritual family sense.
Paul explains that when we first come to this world, we are underage in matters
of the spirit and therefore under law and tossed about by the principles and
principalities of this world. We have not yet known God for ourselves to be
transformed by the new birth, and therefore we are slaves and so cannot be heirs
of the promise which is to sons.
However, since Jesus came and died for the world, the ungodly, the slaves, when
we accept His salvation, we are born again, and are adopted into God’s family as
spiritual sons in the lineage of Jesus. We are now rightful heirs to the promise, and
are now children in Steps two and three of our earlier discussions. This creates a
clear distinction of one of the reasons we are either just people of God, children
according to the flesh, or spiritual children of God, born again and adopted to His
family as heirs together with Jesus.
A second analogy of why we are either children according to the flesh, or heirs
according to the promise, is demonstrated in the lives of the two sons of Isaac. Like
his father, Isaac too had two sons. But unlike his father, both his children were
twins, biological sons of Isaac and his wife Rebecca. However, we see God in
Genesis naming Isaac’s descendants after the younger son, Jacob, while the elder
son, Esau, is excluded from the promise. So what went wrong?
Isaac and Rebecca also struggled to have children, but Isaac prayed and God
answered His prayer and Rebecca became pregnant. While the children were still
in her womb, God spoke to her thus: