It took two hours of talking with architect Santiago Calatrava—we touched on rock climbing, the Swiss cheese dish raclette, Rembrandt’s self-portraits and New York City’s tradition of great civic architecture—before I realized how appropriate the placement is of St. Nicholas Greek Orthodox Church, which will overlook the 9/11 Memorial.

And not just because it’s the rebirth of the church, a fixture in the neighborhood since the 19th century until it was destroyed by the collapse of the World Trade Center’s south tower on Sept....