Galatians 4:4–7 (NKJV)
4 But when the fullness of the time had come, God sent forth His Son, born of a woman, born under the law, 5 to redeem those who were under the law, that we might receive the adoption as sons.
6 And because you are sons, God has sent forth the Spirit of His Son into your hearts, crying out, “Abba, Father!” 7 Therefore you are no longer a slave but a son, and if a son, then an heir of God through Christ.
I The Blessing of Adoption
II The Enjoyment of Sonship
III Our Duties to our Father in Heaven as His adopted children
This is the apex of privilege and blessing secured by Christ’s redemption — we receive the adoption.