Paul continues with his discussion from the end of chapter three. A heir is no better than a slave until he has come of age. The Galatians have come of age through Jesus Christ and were adopted into God’s family when they believed. Why would they turn back to the law and become slaves again? Paul reminds them that they received him joyfully when he first came, and eagerly accepted his message. Shouldn’t they listen to him now, instead of to those who are trying to deceive them? Perhaps an illustration will help. Abraham had two sons. One represents the law, and the other the promise. They are like Isaac. They are children of the promise! They are free! They have the Spirit! Why would they want to go back to slavery!
Do you ever find yourself doubting the power of grace? Perhaps you wonder if human effort is necessary for salvation. Some religious traditions struggle with that very thing. They elevate baptism, circumcision, communion, or something else as necessary for salvation or as necessary to keep salvation. In truth, there is nothing else needed but Jesus Christ. Jesus is enough!