This psalm deserves its place as the first of the 150 psalms. The themes of the centrality of God's Word and the contrast between the righteous and unrighteous characterize so many of the Psalms and other wisdom literature. But best of all, this psalm has a promise of a blessed (or happy) life for those who distance themselves from evil people and stay close to God's Word. Who doesn't want a happy life? It's guaranteed if you follow the psalm's wisdom.