Reinhold Niebuhr (1892-1971) was born the son of Gustav and Lydia Niebuhr on June 21, 1892, in Wright City, Missouri. He had three siblings, one of whom also became a famous theologian and ethicist, Helmut Richard Niebuhr. Reinhold's first introduction to the Christian faith came through the German Evangelical Synod where his father was a minister, and Elmhurst College, a small denominational high school. He began his formal theological studies at Eden Seminary and completed a master's degree at Yale Divinity School. From Yale, he moved to Detroit, where he was the pastor of a middle-class congregation for 13 years before he accepted an academic position at the interdenominational Union Theological Seminary from 1930 to 1960. Niebuhr was married to Ursula M. Keppel-Compton, and they had two children together, Christopher and Elisabeth. Ursula, a professor of religion at Barnard College, was an intellectually challenging colleague as well as an excellent editor of Niebuhr's work. Reinhold Niebuhr's life and work have influenced the religious and spiritual lives and development of those who study him and his teachings.
The apparently contradictory phrase "pessimistic optimist" that Robert Brown uses to describe Niebuhr alludes to two important aspects of his theology. In An Interpretation of Christian Ethics, he looks at both the possibility of love in the Christian Church as well as the need to realize the limitations of humanity in living it out. Pessimism refers to Niebuhr's emphasis on the sinful nature of humans, so much so that Reinhold resurrected the term "original sin," which led to severe criticism from both philosophers and theologians. Although he later regretted using the term, he intended it not as a reference to Eden or ultimate depravity, but to the simple acknowledgment that sin limits all human endeavors through pride and rebellion against God. In the Gifford lecture series The Nature and Destiny of Man, Niebuhr describes sin as rebellion against God and humanity's place in the universe. Sin is not just a part of the individual person, but also a part of the institutions, communities, and nations of humanity. He believed that democracy was an important part of modern living and the checks and balances of the constitution held back any particular group from gaining too much power. In The Children of Light and the Children of Darkness, Niebuhr described the ability and the need for democracy due to man's "inclination to injustice." The key to Niebuhr's optimism is his belief that although sin is present in humanity, the connection to the transcendence of God provides a different perspective. Humanity is a part of nature, and thus subject to a limited perspective, but each religion attempts to transcend this limit through a connection to an ultimate source of meaning and value. For the Christian, Biblical faith provides this transcendent view and allows humanity to see beyond itself.
In addition to being an active pastor and academic, Niebuhr was also actively involved in politics and social activism. Niebuhr joined with many Jewish leaders and their concerns with poverty and social justice in Detroit. Earlier in his career, he was taken with Marxist thought and was a critic of contemporary American capitalism. He later moved away from some of his socialist ideals, although he never fully gave up on pointing out different social ills and the problems they created for society both in communism and capitalism. His theology made him keenly aware that any type of social structure had the possibility of becoming corrupt, yet these same systems were necessary in controlling the sin inherent in humanity. He published in theological journals, but also in secular political journals as well, and gained support from atheists such as Arthur Schlesinger and Hans Morgenthau who agreed with his social and political views while disagreeing with his theology.
Niebuhr witnessed several important historical events, including the Great Depression, world war, and cold war, and commented on each as a theologian who actively explored the philosophical and political ideas of his day. Although he held to traditional biblical faith, he did not settle for easy answers to the complex problems of his lifetime. For Niebuhr, the Church must be a witness for secular society while remaining self-conscious of its own propensity toward sin. Niebuhr drew from several aspects of the Christian tradition, including the prophets of the Old Testament, the writings of the Apostle Paul, and the work of Christ. He attempted to be faithful to the message of the Christian Church, while making it relevant and understandable to a modern audience.
Niebuhr highlights some important aspects of spiritual development, especially for those in the Christian tradition. First is the importance of looking at sin both in individuals and social structures, especially in regards to pride and power. This reflects the importance of being self-critical and realizing one's limitations; each person has the same capacity for sin in any type of situation. Second, although awareness of sin is important, this concept must be connected with an understanding of the ability of the Church to show the love of God to the world. God brought redemption to humanity through the work of Christ, which has brought a new world and a new understanding of humanity's relationship to the divine and to each other. Third, one's faith and theological concerns should be actively involved in public life, both in the questioning of current cultural and societal norms and issues of social justice and poverty. Spiritual maturity requires being actively involved in facilitating social change and witnessing the love of to God nations.