About 700 mostly young evangelicals convened this week amid the soaring Doric columns of the august Andrew Mellon Auditorium in the Federal Triangle of Washington, D.C. It was the fifth convocation of "Q," which aims to provoke cultural and political conversation among Christians. President Obama sent greetings by video. New York Times columnist David Brooks discussed humility, while his fellow Times columnist Ross Douthat talked politics. Conservative philanthropist Roberta Ahmanson discussed art. Southern Baptist leader Richard Land conversed with Evangelical Left activist Jim Wallis. NPR's Barbara Bradley Hagerty peered into the future of religion and the media. American Enterprise Institute President Arthur Brooks defended capitalism, almost provoking an approving smile from the dour portrait of former Treasury Secretary and financier Andrew Mellon that graced the auditorium's entrance.