O you sons of men, for the words apply to you, how long will you be hard-hearted and gross in mind? Why do ye love vanity and seek after leasing, supposing life here to be a great thing and these few days many, and shrinking from this separation, welcome and pleasant as it is, as if it were really grievous and awful? Are we not to know ourselves? Are we not to cast away visible things? Are we not to look to the things unseen? Are we not, even if we are somewhat grieved, to be on the contrary distressed at our lengthened sojourn, like holy David, who calls things here the tents of darkness, and the place of affliction, and the deep mire, and the shadow of death; because we linger in the tombs we bear about with us, because, though we are gods, we die like men the death of sin?
Gregory Nazianzen, Oration 7 (Panegyric on St. Caesarius)