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The book of Psalms is divided into five broad divisions, each concluding with a doxology: 1-41; 42-72; 73-89; 90-106; and 107-150. The origin and significance of these divisions are uncertain. The whole of Psalms is bracketed by an invitation (Psalm 1) and a grand conclusion (Psalm 150). Two-thirds of the 150 are ascribed to various authors: 73 to David, 12 to Asaph, 10 to the sons of Korah, and so on.

There are various kinds of Psalms, each following a certain structure: laments (for example, Psalms 3, 31, 80); thanksgiving (18, 30, 75); praise (100, 104, 113); salvation history (78, 135, 136); celebration and affirmation (50, 81, 76); wisdom (36, 73) trust (11, 16, 125).

The most common feature of a psalm is its use of couplets. In some couplets, the second line restates the first:

Do not fret because of the wicked;
do not be envious of wrongdoers (Ps. 37:1).

In other couplets, the second line opposes the first:

For the wicked shall be cut off,
but those who wait for the Lord shall inherit the land (Ps. 37:9).

In still other couplets, the second line expands on the first:

And now, O Lord, what do I wait for?
My hope is in you (Ps. 39:7).

Psalms are intense, passionate, gripping, glorious expressions of life: the Hebrews' approach to worship. Truth (as fact or experience) enters the mind through the heart. Doubts are often resolved by "reminding the soul" of what the heart has experienced to be true. Heartfelt exaltation of God results in exultation of the heart.

For more on the Psalms, see How to read the Bible for All Its Worth, by Gordon Fee and Doug Stewart (Zondervan).