Over the course of many years in the service of our mother the Church, let me tell you, there is one sin I have come to fear above all others: certainty. Certainty is the great enemy of unity. Certainty is the deadly enemy of tolerance.
Even Christ was not certain at the end. “My God, My God, why have you forsaken me?” he cried out in his agony at the ninth hour on the cross. Our faith is a living thing precisely because it walks hand in hand with doubt. If there was only certainty and no doubt, there would be no mystery, and therefore no need for faith.