The 16th century Reformer John Calvin once wrote of the Psalms:
"… that which St. Augustine has said is true, that no one is able to sing things worthy of God except that which he has received from him. Therefore, when we have looked thoroughly, and search here and there, we shall not find better songs nor more fitting for the purpose, than the Psalms of David, which the Holy Spirit spoke and made through him. And moreover, when we sing them, we are certain that God puts in our mouths these, as if himself were singing in us to exalt his glory."
"This book I am wont to style an anatomy of all parts of the soul; for no one will discover in himself a single feeling whereof the image is not reflected in this mirror. Nay, all griefs, sorrows, fears, doubts, hopes, cares, anxieties – in short, all those tumultuous agitations wherewith the minds of men are wont to be tossed – the Holy Ghost hath here represented to the life."
If you are new to singing the psalms in worship, you can learn to sing some new tunes here.