One of the reasons that today in the Western church our joy is so fragile and thin is that this truth is so little understood – the truth, namely, that eternal life is laid hold of only by a persevering fight for joy of faith. Joy will not be rugged and durable and deep through suffering where there is no resolve to fight for it. But today, by and large, there is a devil-may-care, cavalier, superficial attitude toward the ongoing, daily intensity of personal joy in Christ, because people do not believe that their eternal life depends on it.
– Piper, John; When I Don’t Desire God: How to Fight for Joy; copyright 2004; Crossway Books; Wheaton, Il.; p. 37