My recommendation is to read the book
“The New Testament Documents - Are They Reliable?” by FF Bruce.
The ENTIRE book is transcribed here on FR. So it’s free and as accessible as reading our posts.
The New Testament Documents - Are They Reliable?
Christian Corps International Libraries ^ | not mentioned | F.F. Bruce
http://www.freerepublic.com/focus/news/2316798/posts
Just exactly how reliable New Testament accounts are depends on exactly what you use them for.
As guides to definitive Christian teachings, they are 100% reliable, 100% of the time, period.
But if you are a scholar, a historian or scientist who asks precise questions about data, such as: "does the account in document A confirm this other account in document B?" then you begin to notice that there are discrepancies not just among the Gospels & Epistles, but also between those and other ancient documents which have somehow survived.
When you begin to put all these documents together, and analyze them, then you start to see a somewhat different historical picture.
The example right here of our understandings about Pontius Pilate is illustrative.
It's the reason I draw distinctions between "facts" as defined by science versus history versus religious faith.