“Love, but take care what you love. Loving and possessing God is what constitutes a happy life. A man is what his love makes him, it transforms the lover into the image of the object loved. That love needs a medium of expression, that need is supplied by prayer…the affectionate reaching out of the mind for God. Our desire for God is the only road that leads to happiness!”

Taken from: "Augustine on Prayer."
You may purchase the book at:
http://www.monksofadoration.org/bk/bookrv3.html

More links to catholic prayers & comments on prayer:
http://www.cptryon.org/prayer/links.html