"The Psalter is of all books of the Bible that book which gives expression to the experimental side of religion. In the law and the prophetic writings, it is God who speaks to his people; in the Psalter, we listen to the saints speaking to God. Hence the Psalter has been at all times that part of Scripture to which believers have most readily turned and upon which they have chiefly depended for the nourishment of the inner religious life of the heart. I say that part of Scripture and not merely that part of the Old Testament, for even taking the Old and the New Testament together the common experience of the people of God will bear us out in affirming that there is nothing in Holy Writ which in our most spiritual moments–when we feel ourselves nearest to God–so faithfully and naturally expresses what we think and feel in our hearts as these songs of the pious Israelites. Our Lord himself, who had a perfect religious experience and lived and walked with God in absolute adjustment of his thoughts and desires to the Father's mind and will; our Lord himself found his inner life portrayed in the Psalter and in some of the highest moments of his ministry borrowed from it the language in which his soul spoke to God, thus recognizing that a more perfect language for communion with God cannot be framed."
(Geerhardus Vos, Songs from the Soul, Grace and Glory)