It is of some interest that the New Testament church soldiered on for some 20 years before anyone wrote down anything that has remained for us to look at. (The fact that transitory papyrus was often used as a writing medium certainly didn’t help.)
So, looking at your Bible, what is your best guess as to which of the New Testament books was written first? Matthew, perhaps? (It is the first one listed, after all.) No. As odd as it seems, the first of all the New Testament documents that we have is Paul’s letter to the Galatians, written 20 years after Christ’s resurrection.
It is hard to explain exactly why this was so. One reason may have been the early Christians’ expectation of the imminent return of Christ. (I think we can safely conclude that none of them imagined that they would be read 2,000 years into the future.) And so the first Gospel to be written wouldn’t appear for another 10 years after Paul’s letters to the Galatians and the Thessalonians. You can place all four of the Gospels between AD 60 and 70. And if we look at what was occurring during this period, we may begin to understand why they were finally written down.