Only in God is man capable of living fully. Without God he is permanently sick. His sickness affects both his happiness and his capacity for happiness. . .In order to be capable of leading a full life, man must stand in a certain relationship to God and obey certain rules. And the capacity for true happiness and joyful living is also dependent on certain conditions of human life, on a serious attitude toward God. When life does not unfold in communion with God, it becomes grey and sordid, calculating and joyless. How must we live in order to be, or to become capable of happiness? The question is one which ought to occupy us now more than ever before. Man should take his happiness as seriously as he takes himself. And he ought to believe God and his own heart when, even in distress and trouble, he has an intuitive feeling that he was created for happiness.
– Father Alfred Delp, S.J.