Thank you for your comments.
You said: Revelation is necessarily a first-person experience, for anyone else, it is hearsay...
Let me begin by saying I agree with you. Paul, Peter, Thomas, and all the rest would not have given their lives for Christ if they did not have a 1st hand revelation given by God. Now you may say Muslims today are dying for their god today, does that testify to the idea that muslims have also had a personal revelation given by God? Well, Jesus said you will know them by their fruit. Muslims dying for their faith are doing so because they are trusting only what they have been told. They are not questioning their religion. They are doing these things not for others but for themselves, because they believe their death will assure sex with virgins and mansions in heaven. Jesus and His 1st disciples were put to death for spreading the message they had received. God has chosen to use both the testimony of others and personal experience to draw us to faith. That is good, because if my faith was based only on my own experience, then I could question myself as being crazy. However, when I hear the testimony of millions of others who have had the same type of experience, it encourages and strengthens my faith.
When I came to faith in God, it was originally based on a personal revelation God gave me. My motive here is not to intellectually save people. My motive here is to break down walls people like my self built up. The walls I built in my own mind blinded me from even considering the possibility that the Bible could be true. I like you had hundreds of reasons to believe the Bible was flawed or just totally false. However, these reasons I had for rejecting the God of the Bible were based on my own collection of misinformation that I had been fed. It was also based on my own selfish love of sin. I did not have an understanding of scripture in context. I would pick things out of context, and read into things. In doing this I missed what the original point of the scripture was. It was only when I let go of my pride and pre-conceived notions of God that He responded to me, when I asked Him to reveal Himself. Ever since then I have been studying the Bible and searching out the answers to all those doubts and questions I had about His word.
Let me also point out that salavtion is not dependent upon how much you know about scripture. Salvation is dependent upon faith in God. God has given us natural knowledge, it is called our conscience. We all know naturally that we have sinned. The reality is that I am no more righteous in and of myself than a mass murderer. If it was not for the grace of God, we all would have the capacity to do such evil. We do not commit such evil because we have been brought up in a positive environment with a chemical balance in our brain that makes it less likely that we would do such a thing. But God is responsible for my environment and my chemical balance. THIS IS NOT TO SAY THAT GOD CREATED MASS MURDERERS. Man created sin, not God. Through God's influence in the world He has kept mankind from destroying himself which is in our sin nature. So the fact that you and I are not mass murderers is a reason for us to give thanks to God for His influence on our hearts. However, Jesus said if w so much as hate someone, we are in danger of the same judgement as a murderer. Hate for someone in God's economy is the same as murder. We look at these things different, but the only difference between someone who hates and a murderer is God's influence in that person's heart preventing him from acting upon that hate.
The only way we can be healed of this disease we have inherited called SIN, is through faith. Faith causes us to deny our natural selfish tendencies, and reach out to our creator. When we do that, God responds to us by revealing Himself to us in an intimate and personal way.
As for your question. You are making a few assertions based on speculation. For example you assert the disciples did not speak Greek. I'm not sure how you could possibly know that. They lived in the Roman empire where Greek was the primary language. But aside from that. Even if they did not speak Greek, it does not matter, because in context of the entire account, it is obvious what Jesus is saying here. Jesus goes on to define what He meant in verses 5 and 6, where He points out that we must not only be born in the flesh, but we must be born of Spirit of God in order to get into heaven.