Fulfillment of desire is ever-active repose in the object of desire. Such repose is eternal uninterrupted enjoyment of this object. Enjoyment of this kind entails participation in supranatural divine realities. This participation consists in the participant becoming like that in which he participates. Such likeness involves, so far as this is possible, an identity with respect to energy between the participant and that in which he participatesby virtue of the likeness. This identity with respect to energy constitutes the deification of the saints.”
-Cap. D. 4.19, PG 90.1312A-B = Ad Thal. 59, PG 90.608C-609B; G. E. H. Palmer, Philip Sherrard and Kallistos Ware, eds., and trans., The Philokalia. The Complete Text, 5 vols. (London, 1979-), 2:239-240.