Perhaps the largest role that religion plays in the lives of the characters of The Falling Man is that of a constant, scar-like reminder and a source of huge change. The protagonist of this book, Keith Neudecker, manages to survive the September 11th terrorist attacks on the World Trade Center and returns home to his estranged wife, Lianne, and their son, Justin. Although Keith walks away with little physical damage, the mental trauma that he endures as a direct "participant" in these events (and the traumas of Lianne and Justin as witnesses) do not fade away.
Lianne finds herself paying much more attention to the ways in which death surrounds her and becomes irritated at the female neighbor who plays loud "Islamic" music from the apartment below; she even resorts to physically attacking this woman. She becomes obsessed with terrorism and the weird "performance" of the street artist who poses as a man leaping to his death from the World Trade Center on that fateful day; it seems that she blames this attack (like many Americans) on Muslims in general rather than being able to articulate the difference between radical factions and peaceful practitioners. Lianne eventually turns to religion as a source of comfort and leaves Keith.
Justin steals a pair of binoculars and searches the sky with a certain youthful paranoia for "Bill Lawston" (Bin Laden); even he seems to have absorbed the persistent fear of another attack (and death) that this religiously-motivated incidence has spurred.
Keith finds himself drawn to another woman, Florence, who also survived the attack. He seems to lose his identity in what the two "know together" and finds himself not caring about being "safe in the world." His outlook changes radically after the attacks, and he eventually finds himself incapable of leading the life he had led before; he abandons his work as a lawyer, becomes a professional poker player, and disappears from his family for long stretches of time, eventually allowing his marriage to re-dissolve.
The book also features an interlude that follows an ex-Iraiqui soldier, Hammad, who aids in planning and executing the terrorist attacks after receiving training in an Afghani jihadist camp. It provides an interesting insight into the motivations and perspectives of those who committed the acts... perhaps the kind of insight Lianne wishes she had earlier in the book.