<<<How certain are you that what we have in scripture was actually (for real) written in the 1st. Century?
How about 4th and 5th Century passed off as 1st Century?
Just asking.>>>
Contemporary evidence, unless you think people like Jerome were liars and entirely made the New Testament books up.
<<<There is no evidence that the gospels were written by apostles. Their present titles come from later tradition and were not part of the gospels themselves; the books are themselves anonymous. Moreover, the traditional authorship of Mark and Luke is not even apostolic; John Mark and Luke were disciples of apostles, not apostles themselves. As for much of the gospels being "virtually identical to each other", this is because they are dependent on each other and on mutual sources. The author of Luke himself noted that earlier gospel accounts lay before him (Luke 1:1-4). About 90% of Mark is reproduced in Matthew and 50% in Luke, usually in the same order, and agreement between Luke and Matthew starts when Mark starts and ends where Mark ends. The gospels of Matthew and Luke are little more than expanded interpolated versions of Mark. As for the common material shared between Matthew and Luke that is not found in Mark, there are two usual explanations of this: the author of Luke used Matthew (the Farrer-Goodacre theory), or both authors used a common source (the popular Q theory). Also note that since Matthew incorporates most of the text of Mark, the traditional claim that Matthew is an eyewitness account by Apostle Matthew is considerably weakened.>>>
It's amazing that something that has as little evidence as the Q theory is considered to be fact or extremely probable by many scholars. I think the ECFs would at least write about the existence of a simple volume of Christ's sayings if it actually did exist. Of course, no one would ever believe what the Gospel of John says, "But the Counselor, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and bring to your remembrance all that I have said to you" (John 14:26). It is traditionally held that the Gospel of Matthew was written in Aramaic and the Gospel of Mark in Greek. I see it as more than possible that the translators of Matthew used the Gospel of Mark as a linguistic basis for their translation. I've also heard that the claim that the Gospel of Matthew was basically copied off of Mark and expanded is not too credible as it would have been physically difficult for a scribe to accomplish this given the unergonimic qualities of writing implements of that time (I don't know much about that idea, though).