Sometimes age and experience force us to reevaluate long held beliefs about the world and the way life works. As idealistic youths in Sunday school and Luther League, for instance, my friends and I vexed and perplexed our ultra-orthodox pastor by arguing against the doctrine of original sin. We were convinced that people were innately and instinctively good. And then we grew up and were "mugged by reality": stung by the selfishness that lies hard by the heart of each and every mortal being, including ourselves. Some among us once believed in some form of elemental fairness and justice in this life. And then we saw virtuous people suffer great hardship and heartache, while others who lived only for themselves prospered and flourished.

Part of growing up is shedding ideas and notions that …