The Beginning Of Perfection

Εἰ καὶ τελείους ἡμᾶς εἶναι ὁ θεῖος βούλεται νόμος, ὁμώνυμε, ἀλλὰ κατὰ ἀνάβασιν καὶ προκοπὴν πρὸςτὴν τελείωσιν φθάσαντας, πρότερον γάλακτι ποτιζομένους, ὡς ἀρτιγένητα βρέφη, καὶ ἐν αὐτῷ εἰς σωτηρίαν αὐξάνοντας. Ἅγιος Ἰσίδωρος Του Πηλουσιώτου, Βιβλίον Πρῶτον, Ἐπιστολὴ ΥΜA' Ἰσιδωρῳ Διακονῳ Source: Migne 78.425a

Even if the Divine law wishes us to be perfect, my namesake, it is necessary that we come to it by ascent and advance, as little infants who are nourished by the drinking of milk and by it grow to salvation. 1 Saint Isidore of Pelusium, Book 1, Letter 441, To Isidore The Deacon 1 1 Pet 2.2