What does the Bible say about God's covenant of mercy?

In Scripture, God's covenant of mercy is highlighted through the relationship between David and Jonathan, where David seeks to show kindness to Mephibosheth for Jonathan's sake. This mirrors the eternal covenant made between the Father and the Son, as found in Ephesians 1:4-5, which states that believers were chosen in Him before the foundation of the world. The covenant emphasizes that mercy is shown not because of our worth, but for the sake of Christ, ensuring that all who are chosen receive mercy, reflecting God's steadfast promise to His people.