By faith

On the promise of an heir to Abraham:

Abraham became old and Sarah was mocked in the land, and still he was God's chosen heir to the promise that in his seed all nations of the earth would be blessed. Would it not be better, then, were he not God's chosen? What is it to be God's chosen? Is it to be denied in youth one's youthful desire in order to have it fulfilled in great travail in old age? But Abraham believed and held firm to the promise. Had Abraham wavered he would have renounced it. He would have said to God: 'So perhaps after all it is not your will that it should happen: then I will give up my desire, it was my only desire, my blessed joy. My soul is upright, I bear no secret grudge because you refused it.' He would not have been forgotten, he would have saved many by his example, yet he would not have become the father of faith: for it it great to give up one's desire, but greater to stick to it after having given it up: it is great to grasp hold of the eternal but greater to stick to the temporal after having given it up.

Soren Kierkegaard, Fear and Trembling (New York: Penguin Books, 1985), pp. 51-52.