But mark both their faith, and their obedience. For though they were in the midst of their work (and you know how greedy a thing fishing is), when they heard His command, they delayed not, ... but "they forsook all and followed," ... Because such is the obedience which Christ seeks of us, as that we delay not even a moment of time.
-St. John Chrysostom, Homily 14 on Matthew 4, 4th Century


Within the visible world, man is as it were a second world; and the same is true of thought within the intelligible world. For man is the herald of heaven and earth, and of all that is in them; while thought interprets the intellect and sense perception, and all that pertains to them. Without man and thought both the sensible and the intelligible worlds would be inarticulate.
-Ilias the Presbyter, Gnomic Anthology IV no. 112, Philokalia Vol. 3 edited by Palmer, Sherrard and Ware; Faber and Faber pg. 61