Answer
Christian realism, as espoused by theologian Reinhold Niebuhr, asserts that human nature is fundamentally flawed, and that sin and self-interest are inevitable aspects of human existence. This perspective acknowledges the tension between Christian ideals and the realities of power and politics. Niebuhr argued that Christians should be realistic about the limitations of human nature and the fallenness of the world, while still striving for justice and peace.