In vain do they think themselves innocent who appropriate to their own use alone those goods which God gave in common; by not giving to others that which they themselves receive, they become homicides and murderers, inasmuch as in keeping for themselves those things which would have alleviated the sufferings of the poor, we may say that they every day cause the death of as many persons as they might have fed and did not.

Gregory I (c. 540 - 604) Bishop of Rome, liturgist, Latin Father, Doctor of the Church [Gregorius I, Saint Gregory the Great, Saint Gregory the Dialogist]

(Attributed)
    (Source)

Quoted in George D. Herron, Between Caesar and Jesus, ch. 4 "Christian Doctrine and Private Property" (1899).