Chapter 3 of When I Don't Desire God...

...is about the nature of that call to fight for joy. Piper takes a few pages to elaborate on why we must fight, quoting the Apostle Paul, "My desire is to depart and be with Christ, for that is far better" (Philippians 1). Far better! Paul says knowing the presence of Christ is better than living! Piper concludes,

"Surely, then, this is worth fighting for. It may feel strange at first, but when we see what is at stake, no battle will seem more important. Loving Christ involves delight in his Person. Without this love no one goes to heaven. Therefore there is no more important struggle in the universe than the struggle to see and savor Christ above all things--the struggle for joy" (Page 35)

.Did I mention you can read this book for free at the Desiring God website? Click here.