How does the concept of God's mercy affirm our assurance of salvation?

God's mercy is a central theme in the understanding of salvation, particularly within Reformed theology, which teaches that salvation is entirely by grace through faith. As noted in the sermon, David appeals for mercy, relying on God's character and covenant promises rather than his own actions. This mercy is everlasting, providing assurance that despite our failures, God remains faithful to His covenant. Psalm 136 reiterates the enduring nature of God's mercy, reminding believers that it is this mercy that forms the solid foundation of our hope in Christ.