Gregory and Plato differ on whether the connection between the soul and the body is maintained after death. For Plato or the Platonists, death means a release of the soul from the body and its purification. The purification thesis of Phaedo, in which the pure soul should abandon the body as much as possible, reflects the cave allegory. In comparison, Gregory makes Macrina, a character in a play, say the following in relation to the thesis of Paul:
The Lord seems to be teaching that we who are living in the flesh (σάρξ) ought as much as possible to separate ourselves and release ourselves from its hold by the life of virtue, so that after death we may not need another death to cleanse us from the remains of the fleshly glue
We can say that, by replacing the word ‘body’ with ‘flesh’, Gregory introduces Paul’s distinction between the body and flesh, and thereby, modifies the theme of the soul’s purification of Plato. Specifically, while flesh is related to human nature in its sinfulness and needs to be purified likewise in the Platonic tradition, the resurrection body somehow retains its material elements that are united with the soul. As a biblical support, he quotes Paul’s assertion that “it is sown a physical body, it is raised a spiritual body” (1 Cor 15:42–44). Thus, unlike in the Platonic tradition, for Gregory the body, distinguished from flesh, need not be abandoned.
S. Tsuchihashi, The Likeness to God and the Imitation of Christ: The Transformation of the Platonic Tradition in Gregory of Nyssa, στό: G. Dunn – W. Mayer (ἐκδ.), Christians shaping identity from the Roman Empire to Byzantium : studies inspired by Pauline Allen [Supplements to Vigiliae Christianae : texts and studies of early Christian life and language 132], Leiden 2015, 113-114.
Κατὰ τὰ ἄλλα, ὁ Νύσσης πλατωνίζει. Συνεπῶς, πρέπει νὰ ποῦμε: Ὄχι μόνο ἡ χριστιανικὴ ἄποψη γιὰ τὸν ἄνθρωπο δὲν εἶναι ἀντιγραφὴ τῆς ἀρχαιοελληνικῆς, ἀλλὰ καὶ εἶναι καλύτερη τῆς ἀρχαιοελληνικῆς κι εὐτυχῶς ποὺ δὲν εἶναι ἀντιγραφή της. Ξεχνᾶνε, βέβαια, ὅλοι ὅτι στὸν Πλάτωνα ἡ μετενσάρκωση συνιστᾶ τιμωρία, καὶ ὄχι -ἀντίθετα μὲ τὶς σημερινὲς νεοεποχίτικες δοξασίες- μιὰ εὐχαριστη ἐναλλακτικὴ τῆς ἀνάστασης ἢ τοῦ ἀθεϊσμοῦ.