How do we know God's mercy is available to sinners?

In Psalm 51, David’s repeated appeals for mercy ('Have mercy upon me, O God') provide powerful evidence of God's readiness to forgive. This not only illustrates the character of God as merciful but also invites believers to approach Him with confidence in their time of need. David’s acknowledgment of his sin, paired with the request for cleansing, underscores the biblical truth that no one is beyond the reach of divine grace when they come with a repentant heart. The mercy of God is not transactional; it is rooted in His covenant faithfulness and the sacrificial love exemplified in Christ, who embodies the ultimate expression of mercy for sinners.