Fee and Stuart (How To Read The Bible For All Its Worth) outline three benefits of the Psalms for both their ancient and modern readers:-

1. ‘The psalms can serve as a guide to worship. By this we mean that the worshiper who seeks to praise God or to appeal to God or to remember God’s benefits can use the psalms as a formal means of expression of his or her thoughts and feelings. A psalm is a carefully composed literary preservation of words designed to be spoken. When a psalm touches on a topic or a theme that we wish to express to the Lord, it can help us express our concerns in spite of our own lack of skill to find the right words.

2. ‘The psalms demonstrate to us how we can relate honestly to God—how to be honest and open in expressing joy, disappointment, anger, or other emotions. On this point they do not so much provide doctrinal instruction as they give, by example, instruction in the godly articulation of even our strongest feelings.

3.  ‘The psalms demonstrate the importance of reflection and meditation on that which God has done for us. They invite us to prayer, to controlled thinking on and discussion of God’s Word (that is what meditation is), and to reflective fellowship with other believers. Such actions help shape in us a life of purity and charity. The Psalms, like no other literature, lift us to a position where we can commune with God, capturing a sense of the greatness of his kingdom and a sense of what living with our heavenly Father for eternity will be like. Even in our darkest moments, when life has become so painful as to seem unendurable, God is with us. “Out of the depths” (Ps 130:1) we wait and watch for the Lord’s deliverance, knowing we can trust God in spite of our feelings. To cry to God for help is not a judgment on God’s faithfulness but an affirmation of it.’