2. The books probably relevant to this discussion—the Gospels—are generally believed to have been written before the turn of the first century. Some argue that Mark and Luke were written as early as the 50s, 20 years after Jesus died. [0]
[0] https://jimmyakin.com/2018/11/when-was-the-gospel-of-mark-wr...
the books we see today are translations of heavily copyedited and consolidated writeups of oral traditions.
scholars like Bart Ehrmann have been very helpful to see that whatever the word of god was, it's deeply hidden behind the words we hold in our hands, and the.words are by no means a historically accurate, literal "truth", but a consensus on what the author's and editors over centuries hold dear as spirtual and religious "true" foundation.
Few who cast unwarranted doubt upon the New Testament realize how extremely sceptical they would have to be about every other piece of ancient writing, because none of them even comes close to the new testament in terms of: 1) number of copies 2) being written close to the time of the actual events
[1] https://crossexamined.org/is-the-new-testament-reliable-erhm...