I'm a little surprised that you'd cite John in support of the truth of John. You really should understood that such self-referential argument carries no weight at all, it's the same fallacy eannassir commits all the time.
For all your claimed wisdom why do you have so much problem grasping a few thing in the Bible that go against 'the norm'? Before I get to that part lets cover that one verse from John in particular. Clearly it is saying that there was an eye-witness, that being true or not also has bearing on if this verse below is true or not. Now it is easy to see which path you took. If you are comfortable with that (the word God actually throws you into turmoil BTW) that's fine. To get there you had to go through a series 'if/then' questions. Rather than that part that got you to where you are now I want to talk about the part of the 'if/then' cycle that was the 'version you would have had adopted if you had believed verses like the two referenced so far. The letter the verse come from would have been from an Apostle like Peter or Andrew (most likely Andrew as him and the beloved were the two that John sent to follow Jesus). So lets take the CIA magic marker and black out anything said by John (for starters) and we have your version of things. What did your version look like when you still applied this rule as part of the requirements for understanding the Holy Bible, not just Revelation. Right off the bat you are going to accuse me of 'laying a curse on you', guess what, you can't be cursed but you can be deceived and you can do it to yourself. You have freely added things from history books as 'proof' your version is right and all you have done is change the story that makes the Bible appear to be more of a burden on people than what is written without the embellishments you insist are needed. Your 'little trick' also removes you from being able to be saved.
Is your current version altered if you take things as presented in the KJV version that is freely available today, (whole passages determine the meaning rather than a single verse setting policy) that is the only reference you can use what changes take place in the two examples below, rather than a long detailed reply a simple .changes are needed. or .changes are not needed. will do.
Re:22:18:
For I testify unto every man that heareth the words of the prophecy of this book,
If any man shall add unto these things,
God shall add unto him the plagues that are written in this book:
Re:22:19:
And if any man shall take away from the words of the book of this prophecy,
God shall take away his part out of the book of life,
and out of the holy city,
and from the things which are written in this book.
1Jo:1:1:
That which was from the beginning,
which we have heard,
which we have seen with our eyes,
which we have looked upon,
and our hands have handled,
of the Word of life;
Example #1 In Daniel 6 there are many versions of who the 'he' is that is mentioned in relation to a covenant. Does your version change if you are 'forced' to use this verse just below to define who the 'he' is later in the same passage.
Da:9:4:
And I prayed unto the LORD my God,
and made my confession,
and said,
O Lord,
the great and dreadful God,
keeping the covenant and mercy to them that love him,
and to them that keep his commandments;
Example #2 You have to take the two references to the 'end of sacrifice' as being the same event rather than your urrent that has the first 'end of sacrifice' happening before Jesus is taken to the temple by His mother so she can make the required sacrifice in the Temple. (Lu:2:22-30

The moneychangers is proof blood sacrifice never came to an end. Pick the true abomination, a Gentile spilling pig's blood or the leaders of the Jewish people plotting to kill one of their own because He is a threat to their 'position in society'. Now compare the pig's blood to what the temple leaders did to Stephen. Which pages of your books cover that aspect of things?
Da:8:11:
Yea,
he magnified himself even to the prince of the host,
and by him the daily sacrifice was taken away,
and the place of his sanctuary was cast down.
Da:9:27:
And he shall confirm the covenant with many for one week:
and in the midst of the week he shall cause the sacrifice and the oblation to cease,
and for the overspreading of abominations he shall make it desolate,
even until the consummation,
and that determined shall be poured upon the desolate.
The real reason we differ on what the Bible's final message is, is because you take it all as literally true (except when it's convenient for your interpretation not to) and think it has one, and I don't.
The Bible's message can be understood by reading the first 3 and last 3 chapters. The part of what happens in between those two points is not quite as easy to understand just because the events are broken up into little flashes of info rather than all info in one spot.
Biblical scholarship is pretty much unanimous that Mark was the first gospel written,
That would appear to be somewhat less than 100% agreement. So when Paul and everybody was wandering around outside of Israel teaching in the synagogues they came with empty hands and no manuscripts and Jesus's promise to them about sending the Holy Spirit to help them remember His exact words was (at the earliest 30 years and as late as 70 years after the cross. This would also seem to promote that the Gospel and the Epistles and Revelation were all written in one sitting while on Patmos. You 'scholors' can't even prove that Matthew, Mark, and Luke were written out by the end of the first week Jesus was out of the grave. John's version covers events past that first week but that brings up this question. The 4 writers were baptised the first night Jesus was out of the grave. Anytime after that the writing could have started. By the time Peter had his vision about taking the Gospel to the Gentiles there could have been more than a few copies of the 4 Gospels already copied from some original documents. That would have been part of the mission when in places outside of Israel. Take the 4 with you and at each stop have a scribe make a copy so they could study it after the Apostles left with the originals to visit the next town. The original could have been in Hebrew and translated into Greek in the synagogues that were visited on journeys like Paul took. Those places would have already had copies of the OT. You don't go on a mission to 'publish' when you have nothing on hand to publish.
and that it seems most likely to have been written no earlier than around the year 64,
Again you admit it is speculation, by 64 AD the epistles of John should have been in print also, as well as acts and James and Peter. Jude and Revelation could have been the only two books left out by 64AD.
and possibly as late as 70.
The Epistles of John were written wile in the Nations but before being transferred to Patmos and visits were mentioned and after 70 AD Jews were not wandering around with the same freedoms they have prior to the revolt the Jews in Jerusalem were staging.
Matthew and Luke clearly used it as a source, so they must post-date it.
Clearly??? Not all 3 accounts say the same thing.
M'r:9:2: And after six days
M't:17:1: And after six days
Lu:9:28: And it came to pass about an eight days
Jesus told them they would have help remembering what He said to them, perhaps that is why they are so similar. The copied book should be the largest, not the smallest and least detailed.
Luke is probably later than Matthew, and both are generally dated between 70 and 80.
So until then everything was repeated just as the Torah was verbal only until the captivity in Babylon.
So John and all 5 books were void untill about 100 AD when the misssion was to get the word out far and wide ASAP. Putting off a task that couild have been started almost 70 years earlier, and you see nothing wrong with the 'thinkers' who came up with that supposition? To what lengths did you question it before deciding they were right and the Bible got it wrong ... again.
It was clearly known to other Christian writers by the year 150, and its origins are generally dated to sometime around or shortly after 100.
That is what the RCC clearly promotes as the truth, need I remind you they are in danger of having their nuts cut off for the lies and deceptions that are in the news even these days.
And just in case you missed the obvious conclusion from that, it means the gospels were written several generations after Jesus time, and not by the apostles whose names they bear.
Perhaps you missed the jump from 'speculation' (less than 100% certainty) to you promoting their thoughts as being 100% provable
That's a heresy only to a fundamentalist Christian; it's the clear consensus of biblical scholarship.
None of whom have the same satnding with God as the Apostles had. You choose to belive men who were obviously not around to determine if the Gospels are eye-witness accounts or not over the Gospels version of things. Without their 'help' you would be clieless about the Bible's message. That isn't an insult and my two examples above would show that to be true. You are relying on one set of possibilities (for both example #1 and #2). You scholors should have covered those two possibilities, show me some papers that cover just those two aspects.