“Let everything that has breath praise the Lord.” This phrase characterizes what is meant to be the supreme effect of reading the Psalms. The focus of the Psalms is worship through all the events and ups and downs of life. Psalms is comprised of 150 songs that span from Moses to the post-exilic period and they reflect a vast array of human experiences such as joy, sorrow, abandonment, atonement, tears, renewal, refuge, rest, war, peace, fear, failure, hope, enemies, love, lamentation, praise, and judgment.
In short, the book of Psalms is one of the great poetical books of the Old Testament. Interestingly, there are only five Old Testament books that do not seem to have any poetry. They are: Leviticus, Ruth, Ezra, Haggai, and Malachi.