Reinhold Niebuhr (1892-1971) -- whom President Barack Obama famously named as his "favorite philosopher" in a 2007 interview -- was arguably the most influential American theologian of the twentieth century. Gabriel Fackre's Promise of Reinhold Niebuhr has long provided a compact introduction to Niehbuhr's life and thought. With Niebuhr's enduring legacy again rising to prominence in political and religious circles, Fackre has reworked his...