Psalms directs us into communion with God, lifting up and letting out our hearts towards him.
The scope of them is to assist and to kindle in the souls of men those devout affections which we owe to God as our Creator, owner,ruler and benefactor.
Psalms are used to convey divine life and power and a holy warmth into our affections.
It is of use to be sung.
The Psalmists experinces are of great use for our direction,caution, and encouragement.
In telling us, as he often does, what passes between God and his soul.
They help us to improve our prayers and praises and shows us that there are ways in which we may keep up communion with him in all the various conditions of human life
-MATTHEW HENRY