First, let me explain the problem briefly.
When we use the term "born-again" Christians, we are actually using the term supposedly coined by Christ in St John's Gospel. It appears in Jn 3:3 in the conversation between Jesus and Nicodemus:
3 Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God.
4 Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born?
5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.
6 That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.
Here is where Jesus uses a word play that can only work in Greek. He is saying that unless a man is born from above (ανωθεν), he cannot see the kingdom of God. But as is characteristic of Nicodemus throughout the passage, he seems to misunderstand everything Jesus says. He chooses to look at the word "ανωθεν" as "again" which is possible in Greek although the context should have been obvious. So, Christ, in answering him, has to be more precise and he specifies that a man has to be born "of the spirit".
You may ask what the problem is if it's Nicodemus who is being obtuse. But you see, the conversation between Jesus and Nicodemus was in Aramaic, not Greek. There is no such double meaning in a word that can mean "from above" and "again" in Aramaic. Scholars have known this for a long time but of course faithful Christian scholars don't tell the rest of us anything that can rock our faith. It was Bart Ehrman, a born-again Christian Bible scholar who lost his faith after becoming an expert on the Bible who first publicized this fact to the world.
What Ehrman is saying is that this sacred verse of our Lord from where we got our term "born-again" could not have been said at all since he was speaking a different language.
Some Christian theologians have tried to counter Ehrman but so far, none of them has done so convincingly. The usual way they go about it is to say that the Peshitta uses a word for that verse that is usually translated "again". But that doesn't mean a thing. No serious scholar believes that the Peshitta has the original Gospels or that the Greek Gospels were translated from the Peshitta. The Peshitta displays obvious signs of a Western reading and one important feature of the Peshitta which no apologist will mention is that it tellingly leaves out 2 Peter, 2 and 3 John, Jude and Revelation. One important clergyman in my church has made it clear that he is of the view that Revelation is not rightly canonical and should be removed from the Bible but there are more books than Revelation that are not rightly canonical but that's a subject for a different blog entry.
All I want to say is that the presence in the Peshitta of a word in Jn 3:3 that can be translated "again" does not help us at all. A pious Syriac Christian who translated the Gospels into the Peshitta will of course write "born again". Neither does it help us even if that word in Aramaic has since acquired the meaning of "from above" like its Greek counterpart. We know the power of religion and the devout Syriac Christians will bend over backwards to accommodate what they believe to be the very word used by Christ. Even today, "born again" has acquired a spiritual meaning in English.
Why then was there a word play on "ανωθεν"? Obviously the writer of John's Gospel was a Hellenistic Christian who wrote the entire story in Greek. He knew no Aramaic and employed all the puns and word-plays in Greek without a care in the world. How was he to know that we will one day have scholars who will bother to point out that Jesus could not have said that because he spoke Aramaic and not Greek? How was he to know that there would come a time when we would be bold enough to question his writing and expose its mistakes and inconsistencies to other believers? For the first 1500 years anyone who tried to do that would have been burnt at the stake.