Jesus answered,
Verily, verily, I say unto you, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.
All Commentaries on John 3:5 Go To John 3
Cyril of Alexandria
AD 444
Except a man be born of water and of the Spirit, he cannot enter into the Kingdom of God.
Since the man did not understand as he ought, what the need of being born from above meant, He instructs him with plainer teaching, and sets before him the more open knowledge of the Mystery. For our Lord Jesus Christ was calling the new birth through the Spirit from above, shewing that the Spirit is of the Essence That is above all essences, through Whom we become partakers of the Divine Nature, as enjoying Him Who proceeds from It Essentially, and through Him and in Him re-formed to the Archetype-Beauty, and thus re-born unto newness of life, and re-moulded to the Divine Sonship. But Nicodemus not so understanding the word from above, imagined it was meant that the future birth should take place after the manner of bodies: therefore also falling into imaginations which shut him up in impossibility, he was caught alike senseless and hard of learning. Of necessity therefore does the Saviour answer yet more mildly, as to one more infirm of habit, and removing the veil that seemed to be thrown over His Words, He now says openly, Except a man be born again of water and of the Spirit, he cannot enter into the Kingdom of God. For since man is compound, and not simple in his nature, being combined of two, to wit, the sensible body and intellectual soul, he will require two-fold healing for his new birth akin to both the fore-named. For by the Spirit is the spirit of man sanctified, by the sanctified water again, his body. For as the water poured into the kettle, being associated with the vigour of fire, receives in itself the impress of its efficacy, so through the inworking of the Spirit the sensible water is trans-elemented to a Divine and ineffable efficacy, and sanctifieth those on whom it comes.
