Galatians 4:1-6 New International Version (NIV)

4 What I am saying is that as long as an heir is underage, he is no different from a slave, although he owns the whole estate. ² The heir is subject to guardians and trustees until the time set by his father. ³ So also, when we were underage, we were in slavery under the elemental spiritual forces^[a] of the world. ⁴ But when the set time had fully come, God sent his Son, born of a woman, born under the law, ⁵ to redeem those under the law, that we might receive adoption to sonship.^{[b] 6} Because you are his sons, God sent the Spirit of his Son into our hearts, the Spirit who calls out, “Abba,^[c] Father.”