Why the special pleading? What make you so sure that those parts might not be completely made up...like 13 million Jews do? Historians and [wiki]Historicity of Jesus[/wiki] made me believe they where true history.
Plus there is the Meticulous Care in the Transmission of the Bible that confirmed this belief.
That's all pulled out of people's arses. There is a neutrality warning on the top of the article on the historicity. Of the two facts that scholars supposedly agree on, the baptism uses the criterion of embarrassment, which is as lame as an argument from silence. Then supposedly "most" scholars agree that there was a crucifixion. Those two points in a man's life, if true, allow for an awful load of people.
The second article, is a consensus of believers. The supposed "earliest copy" is A.D. 125, which is a travesty of logic. They are surely referring to Rylands P52, a minute fragment of John, which is dated by handwriting style (paleography), but contradicted by the codex paper it is written on. Dating by handwriting assumes that people would not write in a "ye olde" artificial antique style, and also that all the whole of the style is represented on the fragment. The is an example of one fragment being re-dated because someone found another small part that had a form of punctuation that was not used until a lot later. The second reason it's not sound to use the date 125AD, is that even if the fragment of John is valid, and came from a book which was exactly the same as modern John, there is an assumption that this book was not surrounded by copious fakes. Hurrah, that the church fathers chose a popular fiction of John. If the words on the P52, conflicted with John, they would just say "Oh well, it's just another fake pseudepigrapha", and nobody would worry about it. But if the words match with OUR John, they go HUZZAH!!! Our John must be genuine!!
The curious case of Tertullian's Adversus Marcion
, is that the work starts with an assertion that there are many other variants floating around, and the church surprisingly has the definitive version. Why would it be so necessary to debunk Marcion so precisely, unless you needed to cover up evidence of what he was teaching about the gospel of Luke? http://www.newadvent.org/fathers/03121.htm
It's is argued that you can reconstruct the gospel of Luke from Tertullian's attack on Marcion, but that would only be true, if Tertullian actually wrote it (~207AD). It seems a little strange to me that when you reconstruct Luke from Marcion's text, the parts he used were identical to the modern Luke. I don't think Tertullian offers any explanation of why Marcion ignored Acts (even though it's a part of Luke), or how the church came to have the modern Luke, and all of Marcion's Pauline epistles.
You can research all you like about the authorship of the Pauline epistles, but one thing you will never find is, how the church actually obtained them. No orthodoxy was actually paying attention to them, or quoting them, until Marcion displayed them, around 135AD to continue the then-dominant version of the Chrestos religion. The curious thing about them, is that they don't mention a physical Jesus, which is more consistent with Marcion's religion. Although much is said about Marcion, nothing is known, so when you read about him, it's all layers of re-quoted guesswork and orthodox attacks, passed off as information. The church contends that the Pauline epistles were a bunch of letters, "generally in circulation", prior to 100AD. How they back this up, is unclear to me. How they then obtained them in original form, and also with Acts, is also unclear to me. It's clear that they were created, edited and selected by Jesus-mythers, gnostics and other "heretics".
The Syrian churches used "the" Diatessaron by Tatian, and knew nothing about the epistles. Later, the Diatessaron was then deemed to be heresy, and then viciously attacked out of existence. Another version was written, later.
Another possible way we could know about the contents of the gospel is from the first Apology of Justin Martyr 150AD, which contains numerous quotes that can easily be attributed to Matthew, or sometimes Luke. An orthodox view is that JM was quoting the Diatessaron. When you read Tertullian's Apology it appears to start the same way as Justin's, which tips the reader off to the fact it's a genre, and none of these "Apologies" were ever sent to a Roman emperor. Potentially, it was written by a later Christian. Eusebius lists Justin's Apology, but we suspect Eusebius of forging the Testimonium Flavianum.
So, no. Finding a fragment of one book, John, on codex paper, that you are too scared to carbon date, does not constitute good evidence that your particular faith is better than Marcion's, or any other variant of Christ. It does not really account for the history between 30AD and 180AD, which is more or less left up to church father's imaginations and creative writing skills.