What does Ephesians 1:6 mean?

This act of choosing believers in advance to become part of God's family contributes "to the praise of [God's] glorious grace." God does all things for His own glory. This includes His advance planning of those who will become His children. That should cause every believer a moment of pause. Consider that God, who created all things, specifically chose before the creation of the world that we would be created, live, become a child of God, and one day stay with God for eternity.

This grace is a powerful gift, a blessing given to us from God. Paul will develop grace much more in this letter, mentioning it specifically twelve times in six chapters. In addition, much of chapter 2 and part of chapter 4 specifically focus on grace. Paul begins with grace (Ephesians 1:2), continues with grace, and ends with grace (Ephesians 6:24). His life and letters were clearly influenced by the grace of God at work in him and his desire and calling to communicate it to others.