The Psalms have through 3 millenia been the source of great inspiration for people who want to learn how to pray or just need words to help them pray. I can’t think of any other piece of literature that comes close to that level of impact.
Here’s what Athanasius (d.373) had to say in a letter to a friend about praying the Psalter…
But the marvel with the Psalter is that, barring those prophecies about the Savior and some about the Gentiles, the reader takes all its words upon his lips as though they were his own, written for his special benefit, and takes them and recites them, not as though someone else were speaking or another person’s feelings being described, but as himself speaking of himself, offering the words to God as his own heart’s utterance, just as though he himself had made them up.
It is possible for us, therefore to find in the Psalter not only the reflection of our own soul’s state, together with precept and example for all possible conditions, but also a fit form of words wherewith to please the Lord on each of life’s occasions, words both of repentance and of thankfulness, so that we fall not into sin; for it is not for our actions only that we must give account before the Judge, but also for our every idle word.
(Thanks to Mike Wilkins of Runnymede Community Church in Toronto for the tip on this great article)