God comes down without changing
Let us look also at what Celsus says next, with a grand announcement, in this way: “Further,” he says, “let us take up the argument again from the beginning with more proofs. I say nothing new, only what has long been settled. God is good and beautiful and happy, and is in what is most beautiful and best. If, then, he comes down to men, he must undergo change: a change from good to bad, from beautiful to shameful, from happiness to misery, and from what is best to what is most wicked. Who would choose such a change? Besides, it is the nature of what is mortal to be altered and remoulded, but of what is immortal to remain the same and unchanging. So God would not accept this change either.”
To this, it seems to me, the needful answer is given by explaining what the Scriptures say about the descent of God to human affairs. For this he needs no change, as Celsus thinks we say, nor any turning from good to bad, or from beautiful to shameful, or from happiness to misery, or from what is best to what is most wicked. For, remaining unchangeable in his essence, he comes down to human affairs by his providence and his ordering of things.
We, then, show that the divine writings also speak of God as unchangeable, both in the words “But you are the same” (Psalm 102:27) and in “I have not changed” (Malachi 3:6). But the gods of Epicurus, being made up of atoms and, so far as their structure goes, liable to dissolve, are busy shaking off the atoms that would destroy them. And the god of the Stoics too, since he is a body, at one time has the whole of substance as his ruling part, when the conflagration takes place, and at another comes to be in a part of it, when the world is set in order. For these men have not been able to bring out clearly the natural conception of God as in every way incorruptible, simple, uncompounded and indivisible.
Greek
Ἴδωμεν δὲ καὶ ἅπερ ἑξῆς φησιν ὁ Κέλσος μετὰ μεγάλης ἀπαγγελίας τοῦτον τὸν τρόπον· ἔτι δὲ, φησὶν, ἄνωθεν πλείοσιν ἀποδείξεσιν ἀναλάβωμεν τὸν λόγον, λέγω δὲ οὐδὲν καινὸν ἀλλὰ πάλαι δεδογμένα, ὁ θεὸς ἀγαθός ἐστι καὶ καλὸς καὶ εὐδαίμων καὶ ἐν τῷ καλλίστῳ καὶ ἀρίστῳ· εἰ δὴ ἐς ἀνθρώπους κάτεισι, μεταβολῆς αὐτῷ δεῖ, μεταβολῆς δὲ ἐξ ἀγαθοῦ εἰς κακὸν καὶ ἐκ καλοῦ εἰς αἰσχρὸν καὶ ἐξ εὐδαιμονίας εἰς κακοδαιμονίαν καὶ ἐκ τοῦ ἀρίστου εἰς τὸ πονηρότατον, τίς ἄν οὖν ἕλοιτο τοιαύτην μεταβολήν; καὶ μὲν δὴ τῷ θνητῷ μὲν ἀλλάττεσθαι καὶ μεταπλάττεσθαι φύσις, τῷ δ᾿ ἀθανάτῳ κατὰ τὰ αὐτὰ καὶ ὡσαύτως ἔχειν, οὐκ ἂν οὖν οὐδὲ ταύτην τὴν μεταβολὴν θεὸς δέχοιτο, δοκεῖ δή μοι πρὸς ταῦτα λέγεσθαι τὰ δέοντα διηγησαμένῳ τὴν ἐν ταῖς γραφαῖς λεγομένην κατάβασιν θεοῦ πρὸς τὰ ἀνθρώπινα· εἰς ἣν οὐ μεταβολῆς αὐτῷ δεῖ, ὡς Κέλσος οἴεται ἡμᾶς λέγειν, οὔτε τροπῆς τῆς ἐξ ἀγαθοῦ εἰς κακὸν ἢ ἐκ καλοῦ εἰς αἰσχρὸν ἢ ἐξ εὐδαιμονίας εἰς κακοδαιμονίαν ἢ ἐκ τοῦ ἀρίστου εἰς τὸ πονηρότατον, μένων γὰρ τῇ οὐσίᾳ ἄτρεπτος συγκαταβαίνει τῇ προνοίᾳ καὶ τῇ οἰκονομίᾳ τοῖς ἀνθρωπίνοις πράγμασιν, ἡμεῖς μὲν οὖν καὶ τὰ θεῖα γράμματα παρίσταμεν ἄτρεπτον λέγοντα τὸν θεὸν ἔν τε τῷ „σὺ δὲ ὁ αὐτὸς εἶ“ καὶ ἐν τῷ „οὐκ ἠλλοίωμαι“· οἱ δὲ τοῦ Ἐπικούρου θεοὶ, σύνθετοι ἐξ ἀτόμων τυγχάνοντες καὶ τὸ ὅσον ἐπὶ τῇ συστάσει ἀναλυτοὶ, πραγματεύονται τὰς φθοροποιοὺς ἀτόμους ἀποσείεσθαι,· ἀλλὰ καὶ ὁ τῶν Στωϊκῶν θεὸς, ἅτε σῶμα τυγχάνων, ὁτὲ μὲν ἡγεμονικὸν ἔχει τὴν ὅλην οὐσίαν, ὅταν ἡ ἐκπύρωσις ᾖ· ὁτὲ δὲ ἐπὶ μέρους γίνεται αὐτῆς, ὅταν ᾖ διακόσμησις. οὐδὲ γὰρ δεδύνηνται οὗτοι τρανῶσαι τὴν φυσικὴν τοῦ θεοῦ ἔννοιαν ὡς πάντῃ ἀφθάρτου καὶ ἁπλοῦ καὶ ἀσυνθέτου καὶ ἀδιαιρέτου.