"Marriage […] is, not in lover's language but in cold theological fact, a foretaste of heaven.[…] Heaven is enduring love, love that endures without effort; heaven is a happiness into which the thought of self does not enter; heaven is all giving, and giving without cost. Of all that, we can find no nearer image on earth than the love of man and woman. Only, because it is of earth, that image remains imperfect. Earthly love cannot survive the stress of everyday living without the need of sacrifices on both sides."