Strangely to me, I don't recall that DeWitt makes much reference to comparing "we cannot be born twice" to the "born again" statements of Christianity.
Is being "born again" an obvious question that arises to everyone everywhere? I wonder what the probabilities are that the Epicureans were known for this "can't be born twice" and that that infuenced the use of the analogy.
As for me, if I were an early Christian talking about miraculous salvation, my wishful thinking would focus on "never dying" or "staying young" but remaining at least a young adult. Even if I were a miracle worker I don't think I'd consider being literally "born again" to be particularly appealing, so I doubt I would have normally thought to talk in those terms.
Maybe Dewitt or others argue this somewhere and I am not aware of it.
John 3:1-21
3 Now there was a man of the Pharisees named Nicodemus, a ruler of the Jews. 2 This man came to Jesus[a] by night and said to him, “Rabbi, we know that you are a teacher come from God, for no one can do these signs that you do unless God is with him.” 3 Jesus answered him, “Truly, truly, I say to you, unless one is born again[b] ” he cannot see the kingdom of God. 4 Nicodemus said to him, “How can a man be born when he is old? Can he enter a second time into his mother's womb and be born?” 5 Jesus answered, “Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. 6 That which is born of the flesh is flesh, and that which is born of the Spirit is spirit.[c] 7 Do not marvel that I said to you, ‘You[d] must be born again.’ 8 The wind[e] blows where it wishes, and you hear its sound, but you do not know where it comes from or where it goes. So it is with everyone who is born of the Spirit.”