Excerpt from “Doubt and the Vain Search for Certainty” by Alister McGrath:

To believe in God demands an act of faith—as does the decision not to believe in him. Neither is based upon absolute certainty, nor can they be. To accept Jesus demands a leap of faith—but so does the decision to reject him. To accept Christianity demands faith—and so does the decision to reject it. Both rest upon faith, in that nobody can prove with absolute certainty that Jesus is the Son of God, the risen saviour of humanity—just as nobody can prove with absolute certainty that he is not. The decision, whatever it may be, rests upon faith. There is an element of doubt in each case. Every attitude to Jesus—except the decision not to have any attitude at all!—rests upon faith, not certainty. Faith is not belief without proof, but trust without reservations—a trust in a God who has shown himself worthy of that trust. To use a Trinitarian framework: God the Father makes those promises; God the Son confirms them in his words and deeds; and the Holy Spirit reassures us of their reliability, and seals those promises within our heart.

These points are reflected in the American writer Sheldon Vanauken’s account of his mental wrestling before his conversion at Oxford. He found himself caught in a dilemma over the role of proof in faith, which many others have experienced.

“There is a gap between the probable and the proved. How was I to cross it? If I were to stake my whole life on the risen Christ, I wanted proof. I wanted certainty. I wanted to see him eat a bit of fish. I wanted letters of fire across the sky. I got none of these … It was a question of whether I was to accept him—or reject him. My God! There was a gap behind me as well! Perhaps the leap to acceptance was a horrifying gamble—but what of the leap to rejection? There might be no certainty that Christ was God—but, by God, there was no certainty that he was not. This was not to be borne. I could not reject Jesus. There was only one thing to do once I had seen the gap behind me. I turned away from it, and flung myself over the gap towards Jesus.”

There is indeed a leap of faith involved in Christianity—but it is not an irrational leap into the dark. The Christian experience is that of being caught safely by a loving and living God, whose arms await us as we leap. Martin Luther put this rather well: “Faith is a free surrender and a joyous wager on the unseen, untried and unknown goodness of God.”

Read it all here.