What does Psalm 118:29 mean?

This verse concludes the psalm using identical words as the opening line (Psalm 118:1). For all the Lord's work on behalf of Israel, He deserved the people's thanks and worship. The Lord brought them home from seventy years of captivity (Ezra 2:1). He empowered them to rebuild the temple and Jerusalem's walls (Ezra 3:1–2, 8). Even earlier, the Lord had given His people abundant evidence of His goodness and love.

Believers in the New Testament era also have more than sufficient reason to thank the Lord. He is good to us every day. He meets our needs and answers our prayers. Even more, our experiences and the words of the Bible tell us His love is loyal and unchanging. He expressed love toward us by giving His Son to die for our sins (Romans 5:8; 1 Corinthians 15:3). In love He relates to us as His children (1 John 3:1). Also, in love He has given us an eternal inheritance (Ephesians 1:3–14).