I found this resource today thanks to Challies. The Desiring God website has a bunch of their books available for free download in PDF format. Do yourself a favor and download Don’t Waste Your Life. Here’s a quote:
“God created me—and you—to live with a single, all-embracing,
all-transforming passion—namely, a passion to glorify God
by enjoying and displaying his supreme excellence in all the
spheres of life. Enjoying and displaying are both crucial. If we try
to display the excellence of God without joy in it, we will display
a shell of hypocrisy and create scorn or legalism. But if we claim
to enjoy his excellence and do not display it for others to see and
admire, we deceive ourselves, because the mark of God enthralled
joy is to overflow and expand by extending itself into
the hearts of others. The wasted life is the life without a passion
for the supremacy of God in all things for the joy of all peoples.”
–John Piper, Don’t Waste Your Life

Stumble it!