Even a near-decade before its dedication day, the distinctive eggshell-shaped dome of the First Christian Church prompted minister William “Bill” Alexander to dub it “the church of tomorrow.”

But it almost never saw the light of day. One of a campus of buildings designed by architect Duane Conner in 1956, the unique concrete shape with cutout arches had been deemed of questionable structural integrity by consulting experts. However, in early 1955, a representative of the American Conc...