When the designated time had come, God sent forth his Son born of a woman, born under the law, to deliver from the law those who were subjected to it, so that we might receive our status as adopted sons. The proof that you are sons is the fact that God has sent forth into our hearts the spirit of his Son which cries out "Abba!" ("Father!") You are no longer a slave but a son! And the fact that you are a son makes you an heir, by God's design.