"Once a week Episcopal priest Adrian Dannhauser stands outside her Manhattan church beside a chalkboard sign that reads "Ask me for a blessing (because God knows you need one)." Passersby stop, chat, and ask for prayer: for a sick friend, an addicted son, an upcoming job interview, the state of our nation, or the grief of our world. Bus drivers sometimes open their doors for a quick prayer before the light turns green, and someone once took her to...