The Washington Post and Newsweek are collaborating on a new venture called On Faith, a “conversation on religion” which is actually more of a call and response. Every week or so a question (“Is America a Christian Nation?” “What should we tell children about God?”) is posed to an impressive list of panelists, whose answers spark mostly civil debate in the comments section. This week’s featured panelist is friend-of-the-Revealer Steve Prothero, who takes on the oft-repeated notion that we are all children of Abraham.