History cannot be proven by the scientific method. It can only be done by reviewing the historic documents of the day, and determining if the witnesses are reliable or not.
Now, the age of historic documents can be verified to a certain extent by the scientific method by using techniques that have repeatable results, and also by comparing them to other documents of that same time.
As for the New Testament, the follow source has this information:
Reliability of the New Testament as Historical Documents
- "Astounding" number of ancient manuscripts extant: 5,000 Greek manuscripts, 10,000 Latin and 9,000 other--totaling over 24,000 manuscript copies or portions of the New Testament. These are dated from 100 to 300 years after the originals. (There are no original manuscripts ["autographs"] extant, but the number and similarity of copies allows scholars to reconstruct the originals.)
- Early fragments: John Ryland manuscript 130 A.D. in Egypt; Bodmer manuscript containing most of John's gospel 150-200 A.D.; Magdalen fragment from Mat. 26 believed by some to be within a few years of Jesus' death; Gospel fragments found among the Dead Sea Scrolls dated as early as 50 A.D.
- Comparison with other ancient documents (available copies versus the originals):
Caesar—10 copies—1000 year gap
Tacitus—20 copies—1000 year gap
Plato—7 copies—1200 year gap
- F. F. Bruce: "There is no body of ancient literature in the world which enjoys such a wealth of good attestation as the New Testament."
- William F. Albright: "Thanks to the Qumran discoveries, the New Testament proves to be in fact what it was formerly believed to be: the teaching of Christ and his immediate followers circa.25 and circa. 80 AD."
“History cannot be proven by the scientific method.”
Your theory is flawed.
Some history can indeed be proven by the scientific method.
Not all of it, but some of it.