[2] Niebuhr argued that the Kingdom of God cannot be realized on earth because of the innately corrupt tendencies of society.
[citation needed] Niebuhr argued that human perfectibility was an illusion,[3] highlighting the sinfulness of humanity by naming labor disputes and race riots in industrial hubs like Detroit, Michigan where he pastored, the horrors of the Second World War, the Communist and Fascist totalitarian regimes, and the Holocaust.
"[5] Through his reflections on how the two cities are related, Augustine understood how Christian hope could lead to human responsibility for the problems in the present world.
[6] Christian realism exerted a strong influence on American foreign and domestic policy in the Cold War era.
[9]Conservative think tank Institute on Religion and Democracy, founded in 1981, has adopted the concept of christian realism, on their social and political approaches.
[10] In the post-9/11 era, a number of scholars have been questioning the overly secular character of political realism, especially in the light of postmodern critique.