The Galatians weren’t especially immoral or irreligious. They appear desperate to be right with God, but Paul is astonished that they have turned their backs on grace and are returning to religion. Our standing before God comes from our identity as His children (v26-28). No other distinctions matter.
Galatians 4:1-7 describes “adoption to sonship”, literally as “son placement”. This was a ceremony when the son was declared an adult, with all the rights, powers and privileges of being heir to his family’s wealth, possessions and status. If this ceremony was performed for someone born outside of the family, what we usually mean by “adoption” nowadays, then the old life of the adoptee was completely erased. The child would, in every sense, have a new father and be co-heir with any natural offspring.
Additionally, the now-adult son would be legally empowered to act in the father’s business. The father was publicly affirming the son as someone who carried his authority. He would take the son and acknowledge him as his own – “this is my son, whom I love” – so that everyone knew that authority had been conferred. Our adoption as sons and daughters includes a commissioning to be about the Father’s business. It’s an experience not only of love, but also of trust – “I trust you, I believe in you, and I will back you up as you step out in my name. All the resources of my house are now at your disposal, and I am sending you also to be about my business.”
Satan trembles when we understand that we are God’s children! That’s why the primary focus of spiritual warfare is around the issue of identity. If he cannot stop us from becoming God’s children, Satan will attempt to blind us to what that means, rendering us ineffective. After His baptism, Jesus faced exactly that challenge. In the wilderness, the enemy’s tried to plant seeds of doubt in Jesus’ mind (“IF you are the Son of God…”). Jesus refused to play that game and kept responding that what was written in Scripture was enough for Him. It says that after the devil departed in defeat Jesus, “returned to Galilee in the power of the Spirit” (Luke 4:14), and only then began His ministry of signs and wonders.
Don’t strive to become who God has already declared you to be; simply accept it and pick up the authority that goes with your identity.