A peculiarity of these letters is that they feature a dialogue between friends who agree: the practice and theory of prayer can only illuminate each other mutually. There is never purely theoretical speculation; rather, it always starts from a real experience of successful or failed prayer. The means for better praying is sought nowhere else than in a deeper understanding of what it should be in light of the truth about God and humanity, about sinners and the Redeemer. C.S. Lewis cannot separate seriousness and humor in his tracts, novels, and fairy tales, even though he has looked into the terrible depths of the world's guilt and the cross like few others and dares to speak of the "tragic creator, yes, the tragic redeemer." But in the end, it is all grace. "There! I've done it again! I know my tendency to use images like play and dance for the highest things is a stumbling block for you." But it is not frivolity that is meant; rather, it is ultimately "the perfect marriage of boundless freedom with order, the most balanced, intricate, supple, and beautiful order. Joy is the serious business of heaven." C.S. Lewis conveys the joy in the serious business of our praying.