How do we know that God cannot allow sin to go unpunished?

God's holiness is a central aspect of His character which necessitates that He cannot allow sin to go unpunished. In Joshua 24:19, it is stated that God is a holy and jealous God who will not forgive transgressions unless they are addressed. This reality emphasizes the seriousness of sin and the need for a savior. Ultimately, it is through the sacrificial death of Christ that God’s justice is satisfied, allowing Him to forgive sin without compromising His holiness. Thus, God's nature demands that sin is dealt with, and for believers, the punishment was placed upon Christ.