Doubt is useful for a while

From Yann Martel's thought-provoking novel, Life of Pi:

I'll be honest about it. It is not atheists who get stuck in my craw, but agnostics. Doubt is useful for a while. We must all pass through the garden of Gethsemane. If Christ played with doubt, so must we. If Christ spent an anguished night in prayer, if he burst out from the cross, "My God, my God, why have you forsaken me?" then surely we are permitted to doubt. But we must move on. To choose doubt as a philosophy of life is akin to choosing immobility as a means of transportation.