Letter 1094: Anger is a fire: useful when controlled, devastating when unleashed.

To Theon. On the text: "To those who are the called according to purpose." [Romans 8:28] Divine grace, blended with human eagerness, saves the human being. This is why he who had Christ speaking within him said: "He works together with those who are the called according to purpose." For it was not the calling alone that accomplished salvation (since all were indeed called, but not all obeyed), but also the purpose of those who were called. For the calling did not come about by compulsion, nor by force, but voluntarily.

Εἰς τό· « Τοῖς κατὰ πρόθεσιν κλητοῖς οὖσιν. » Ἡ θεία χάρις (55) τῇ ἀνθρωπίνῃ κιρνωμένη (56) προθυμίᾳ, σώζει τὸν ἄνθρωπον. Δίπερ καὶ ὁ τὸν Χριστὸν ἔχων ἐν ἑαυτῷ λαλοῦντα εἶπε· « Συνεργεῖ τοῖς κατὰ πρόθεσιν κλητοῖς οὖσιν. » Οὐ γὰρ ἡ κλῆσις μόνον (πάντες γὰρ ἐκλήθησαν μέν, οὐχ ὑπήκουσαν δέ)· ἀλλὰ καὶ πρόθεσις τῶν κεκλημένων τὴν σωτηρίαν εἰργάσατο. Οὐ γὰρ ἠναγκασμένη γέγονεν ἡ κλῆσις, οὐδὲ βεβιασμένη, ἀλλ’ ἑκούσιος.