Is there anything unique about Christianity? The incarnation of god’s appearing in human form or religious accounts of return from death are shared by various religious traditions. The respected author, C. S. Lewis when asked what is Christianity’s unique contribution among world religions he replied: “Oh, that’s easy. It’s grace.” This may be, it seems to me, the contrast between a Math of Merit, on the one hand, and the Math of Grace, on the other hand. (A contrast suggested by Philip Yancey in his book Amazing Grace) Lewis in his autobiography, Surprised By Joy had a conversion experience when confronted by THE NEW MATH OF GRACE. What catches one’s attention in Jesus’ parable of the Prodigal Son is that if the Prodigal had lived economically after leaving home with his inheritance he would never have thought of returning home. Seems the Prodigal Son experienced despair and guilt for having left home and squandering his inheritance. Where to turn? I’m going home in spite of my having left. What awaits me there? Little did he, (or do we) know that he (we) would be Surpised By Joy and welcomed to a feast of grace. That’s the New Math of Grace, not the Math of the Prodigal’s (or my/our) merit. It is this New Math of Grace that Lewis suggests is unique to Christianity. Grace now becomes motivation for a life lived with a Faith Active in Love.