More than 150 leaders across a spectrum of conservative Christianity on Friday released a 4,700-word document vowing civil disobedience if they are forced to take part in "anti-life acts" or bless gay marriages.

Called the "Manhattan Declaration," the six-page, single-spaced document was drafted by Prison Fellowship founder Charles Colson, an evangelical, and Princeton University professor Robert P. George, a Roman Catholic, and included a bevy of Catholic, Anglican and Orthodox bishops, archbishops and cardinals as signatories along with dozens of clergy and laity...