Jordan Smith crowns him the Zelig of theologians, for being coopted by both conservatives and liberals:
In his magnum opus, The Nature and Destiny of Man (1941), Niebuhr wrote that the Christian is "'both sinner and righteous' … Christ is what we ought to be and also what we cannot be." A wise man recognizes "that the power of God is in us and the power of God is against us in judgement and mercy." If this sounds paradoxical, that was the point. He had the sermonizer's appreciation of the power of contradictions to heighten moral awareness.
Jackson Lears expands on those inherent contradictions:
As [Sidney Hook] observed with grudging admiration: "There must be something extremely paradoxical in the thought of Reinhold Niebuhr to make so many who are so far apart in their allegiances feel so akin to him." Niebuhr would have loved the characterization: "paradox" was one of his favorite words. How could it not be, for a Protestant intellectual who embraced the contradictions of his beliefs—losing all to gain all, cultivating doubt to deepen faith?
Meghan Clark connects Niebuhr's writings to our conceptions about wealth and holiness today. And Joseph A. Komonchak contrasts the theologian with John Courtney Murray.
The Dish 