Letter 867: The priesthood is a sacred trust, not a career.

To Peter. On the Arians and Eunomians. [two fourth-century anti-Nicene movements denying the full divinity of the Son] Heretics do not perceive that by the very means through which they construct their arguments they are caught by these same means, and that by the very things through which they suppose they are winning they are by these same things brilliantly defeated. For if the Son is a created thing, then not even the term "greater" stands, by their own reasoning. For "greater" is spoken from comparison, and not from an incomparable preeminence. What comparison, then, does a created thing have with the Creator? Let the wise ones say.

Περὶ Ἀρειανῶν καὶ Εὐνομιανῶν. Λανθάνουσιν αἱρετικοὶ δι᾿ ὧν κατασκευάζουσι, διὰ τούτων ἁλισκόμενοι, καὶ δι᾿ ὧν νικᾷν οἴονται, διὰ τούτων λαμπρῶς ἡττώμενοι. Εἰ γὰρ κτίσμα ἐστὶν ὁ Υἱὸς, οὐδὲ τὸ μεῖζον κατ᾿ αὐτοὺς ἵσταται. Τὸ γὰρ μεῖζον λέγεται ἐκ συγκρίσεως, καὶ οὐκ ἐκ τῆς ἀσυγκρίτου ὑπεροχῆς. Ποίαν οὖν σύγκρισιν ἔχει τὸ κτίσμα πρὸς τὸν Κτίστην; λεγέτωσαν οἱ σοφοί.