God's will for humanity and the adversary's plot
Cyril is opening his homily by stating the lemma from Isaiah and then beginning his narrative about God's intention for humanity and the adversary's opposition.
The God of all things, since he is life and life-giving, willed that humanity be an incorruptible living creature on earth, even though its nature is corruptible. But the adversary, because he was wicked and envious, plotted against the human race. He was opposing the will of the Creator. He cunningly brought humanity down into disobedience, knowing that through it humanity would fall into death.
Greek
Τοῦ αὐτοῦ ἐξ ὁμιλίας ῥηθείσης ἐν τῇ Κυρίνου ἐκκλησίᾳ, τρισκαιδεκάτῃ τοῦ φαμενὼθ μηνὸς κατ' Αἰγυπτίους, ἐν ᾗ τὸ τοῦ Ἠσαΐου ῥητὸν ἑρμηνεύει τὸ φάσκον· Κατέπιεν ὁ θάνατος ἰσχύσας καὶ πάλιν ἀφεῖλεν ὁ θεὸς πᾶν δάκρυον ἀπὸ παντὸς προσώπου. Ὁ μὲν γὰρ τῶν ὅλων θεός, ἅτε δὴ ζωὴ καὶ ζωοποιὸς ὑπάρχων, ἄφθαρτον ἐπὶ γῆς ζῷον ἠθέλησεν εἶναι τὸν ἄνθρωπον, εἰ <καὶ> φύσεώς ἐστι φθαρτῆς. Ὁ δέ, ἐπείπερ ἦν πονηρὸς καὶ βάσκανος, ἐπεβούλευσε τῷ γένει, ἀντετάττετο τῇ βουλήσει τοῦ δημιουργοῦ, κατεκόμισε πανούργως εἰς παρακοήν, εἰδὼς ὅτι πεσεῖται δι' αὐτῆς εἰς θάνατον.