Read Galatians 4.
Paul’s plea to the Galatians continued in this chapter, and it was a very anxious plea!
To Paul, following the law is like being under someone else’s control as a child or even a slave would be (vv. 1-3). By contrast, believing in Christ is like being a fully adopted adult son (vv. 4-7). In Christ, we are free and equipped to know and love God.
So why would anyone choose following the law over believing in Christ? To do that would make you like a minor again (vv. 8-11) instead of having all the wealth, blessings, rights, and privileges that an adult heir would receive from his father. It’s like choosing to be Ishmael instead of Isaac (vv. 24-31); nobody would make that choice, but that’s what subjecting yourself to the law is, spiritually speaking.
Within Paul’s explanation about this he described one of the benefits of believing in Christ. Christ died for our sins so that “we might receive adoption to sonship” (v. 5). Adoption is such a great metaphor for what God has done for us in Christ. When a couple adopts a child, that child is conferred–credited–with all the rights and privileges that a natural-born child has. In the same way, by adopting us in Christ, God gives us the same status of sonship as Christ himself.
But “status” is not something we experience, at least not in this life. If we are going to relate to God as his sons, we need more than just status. So God did something else for us so that we could benefit from our status as sons in this life. As Paul put it in verse 6, “Because you are his sons, God sent the Spirit of his Son into our hearts, the Spirit who calls out, ‘Abba, Father.’” The reason why we can experience assurance of our salvation is that we have the Spirit within us that speaks truth to us about our relationship to God as his sons now in Christ. The reason we can pray in faith that God hears us is that the Holy Spirit within us calls out to him.
This gives us hope for a future eternity with God. As verse 7 put it, “So you are no longer a slave, but God’s child; and since you are his child, God has made you also an heir.” Christ promised an inheritance to us in his eternal kingdom; that inheritance comes from the status we received as a gift of grace from Jesus.