Ever since the movement’s utopian awakening during the peace-and-love days of the hippies, Christian rock has produced an astonishing number of stylistic offshoots. Whereas Stryper pump out life-affirming anthems full of pop-metal hot licks and glass-shattering shrieks, Jars of Clay create an entirely different sound, one dipped in ’90s alt-rock edginess. The music’s popularity has mushroomed over the years, particularly in the 21st century, when the lines between sacred and secular have been blurred thanks in large part to crossover successes like the gothic-rock-tinged Evanescence and the punkish Relient K.