“This means that it is not the children of the flesh who are the children of God, but the children of the promise are counted as offspring” (v8). Paul taught that physical descent from Abraham did define God’s people. Instead, the Israelites were “children of the promise” – children born through Isaac, the fulfilment of God’s promise to barren Sarah, and later through Jacob, the younger son. God’s mercy cannot be limited by ethnic boundaries or controlled by human power (v15).
“Whoever believes in him will not be put to shame” (v33). The world uses shame as a weapon to keep people in bondage, but by believing in Jesus we are children of God’s promises, set free (v30-32).