How do we know God's mercy is sufficient for our prayers?

David emphasizes in Psalm 5 that true prayer is approached in the 'multitude of Thy mercy.' This suggests that our ability to come before God in prayer is solely grounded in His mercy towards us. According to Scripture, God's mercy is present in the heart of the Gospel, as He does not impose the punishment we deserve for our sins upon His children, but instead poured it out on Christ, our substitute. The doctrine of mercy reminds us that it is not through our own righteousness but through God's grace that we can approach Him. Therefore, in every prayer, we must acknowledge our reliance on His mercy, knowing that He delights in showing grace to those who are humble and contrite (Isaiah 66:2).