Christians do not earn eternal life by keeping God’s Law; salvation is a gift, purchased by Christ and received through faith. Yet belonging to God’s family changes how we live. Paul warns Christians against persisting in a life characterized by unrepentant sin, while reminding those who struggle with sin and repent that they have been washed, forgiven, and justified in Christ. Through Baptism, the Word, and the Lord’s Supper, Christians are continually reminded of who they are in Christ. Therefore, they are called to “be who you are” by walking according to the Spirit, confessing sin, guarding against temptation, and continually taking refuge in Jesus.

The Law does not replace God's promise of salvation through Christ. The Law instead exposes our sin and self-righteousness, showing us our need for a Savior. Christ has fulfilled the Law, borne our sins, and gives us eternal life as a free gift. There are no hidden conditions—we are beneficiaries of God's promise in Christ.

Paul contrasts the ministry of the Law, which exposes our sin and brings condemnation, with the ministry of the Spirit, which brings righteousness and life through Christ. Like the deaf and mute man whom Jesus healed, sinners cannot open their own ears or tongues to God’s grace. But Christ still says, “Ephphatha—be opened,” opening our ears through His Word, Baptism, Absolution, and the Lord’s Supper. In Christ, we no longer stand before God on the strength of our own righteousness, but as living letters of Christ, bearing the righteousness He has given us. 

Cain’s story warns of the danger of “doubling down” on sin. Pride led to jealousy, anger, murder, lies, and despair because Cain refused to repent and trust in God’s mercy. Sin can work the same way in our lives, leading one sin into another when we justify ourselves rather than confessing our need for forgiveness. The answer is not found in our own efforts, but in faith. We are justified not by our works, but by trusting in God’s mercy through Christ, the true Lamb of God, whose perfect sacrifice covers our sin. Rather than doubling down on sin, we are called to “double up” on God’s mercy, trusting Christ, receiving His forgiveness, and living in joyful gratitude.