@cicerone imposter,
He was a Protestant theologian. Most people are very familiar with his most famous piece of writing without having any idea that he is the author of this popular piece. (I didn't know it until recently, although was familiar with some other of Niebuhr's writing from philosophy courses as an undergrad.) I refer to what is usually called The Serenity Prayer:
God, grant me the serenity to accept the things I cannot change,
the courage to change the things I can
and the wisdom to know the difference.
It's become a mantra at many A.A. meetings. And you can bet that most of the people who say it have no idea that Niebuhr wrote it.
