In Hamza Yusuf's new book, Purification of the Heart...

"If we examine the trials and tribulations all over earth, we’ll find they are rooted in human hearts. Covetousness, the desire to aggress and exploit, the longing to pilfer natural resources, the inordinate love of wealth, and other maladies are manifestations of diseases found nowhere but in the heart. Every criminal, miser, abuser, scoffer, embezzler, and hateful person does what he or she does because of a diseased heart. So if you want to change our world, do not begin by rectifying the outward. Instead, change the condition of the inward. It is from the unseen world that the phenomenal world emerges, and it is from the unseen realm of our hearts that all actions spring. . . . We of the modern world are reluctant to ask ourselves—when we look at the terrible things happening—“Why do they occur?” And if we ask that with sincerity, the answer will come back in no uncertain terms: all of this is from our own selves. In so many ways, we have brought this upon ourselves. This is the only empowering position that we can take." — Excerpted from the Introduction