How do we know God can forgive our sins?

God's ability to forgive sins is rooted in His nature as both just and merciful. In the sermon, it is emphasized that sin must be punished because of God's holy nature. However, God has provided a means of forgiveness through Jesus Christ, who satisfied the righteous demands of the law by bearing the penalty for our sins on the cross. This is illustrated in Jonah's experience, as God relented from sending destruction upon Nineveh not because of their merit, but because of His grace, foreshadowing the ultimate sacrifice of Christ. Therefore, we can be assured of God's forgiveness and mercy as we trust in Christ for salvation.