What does Psalm 33:12 mean?

This verse holds a great promise for the nation that honors God as its God (Proverbs 14:34). David rejoiced that Israel's God was the true God. He refers to Israel as "blessed," meaning "spiritually prosperous" or "happy." In Deuteronomy 4:20 we learn that the Lord chose Israel. Addressing Israel, Moses announces: "But the LORD has taken you and brought you out of the iron furnace, out of Egypt, to be a people of his own inheritance, as you are this day."

Whether the literal nation of Israel, or those who come to faith in Christ, the people of God have no reason to boast about their special relationship to God. The relationship is not rooted in human merit but in divine mercy. Today, Christians are God's people by grace. Ephesians 2:8–9 makes it clear that salvation is entirely a work of divine grace, not of works, so no one can boast. Reflecting on Christians' relationship to God, the apostle John writes: "See what kind of love the Father has given to us, that we should be called children of God; and so we are" (1 John 3:1).