How do we know that God saves His people by grace?

The Bible asserts that God's choice to save certain individuals, such as Noah and the Israelites, is rooted purely in His grace and not in any merit they possessed. Deuteronomy 7:7-8 emphasizes that Israel was chosen not for their number or stature but out of God's love and the oath made to their forefathers. This theme of God's sovereign grace is repeated throughout Scripture, particularly in Romans 9, which discusses God's unmerited favor in salvation, highlighting that our salvation is not based on works but solely on His grace.