How do we know that God can be just and still justify sinners?

The critical question of how God can be just and still justify sinners is answered through the work of Christ. The cross not only displays God's mercy but also His justice. Christ, as our substitute, bore the full penalty for sin, allowing God to remain faithful to His justice while granting mercy to those who believe. In Romans 3:26, Paul affirms this by stating that God is both just and the justifier of the one who has faith in Jesus. Thus, Christ's sacrifice enables God to maintain His holiness and righteousness while forgiving sinners.