How do we know God shows mercy to whom He chooses?

The narrative of Ruth underscores the sovereignty of God in extending mercy to whomever He wills. Ruth, a Moabite and previously an outcast, became a recipient of God's grace simply because God chose to show her mercy. This illustrates a fundamental truth in Reformed theology: God's choice in salvation is not based on human merit but is an expression of His sovereign will. As affirmed in Ephesians 1:4-5, God predestines His elect, showcasing that the mercy dispensed is aligned with His divine purpose and plan.