Unlike the Old Testament, the New Testament was written in a single lifespan by a relatively small group of individuals. The New Testament was written by less than a dozen men who were all very closely associated with one another. We don’t know the exact date, but the first New Testament book written was probably the letter James which might have been written as early as 45 A.D. The earliest gospel was either the gospel of Mark or Matthew, but it is impossible to be certain whe they were written. Some of Paul’s letters, Galatians and 1 & 2 Thessalonians, were written fairly early in the course of New Testament writings. All these books were probably written sometime between 50-55 AD (20-25 years after Jesus’ death and the beginning of the Christian church). Most of the rest of the books were written in the 60’s. The gospel of John and all three of John’s epistles were probably were written in the mid 80’s. The last book of the Bible to be written is also the last book in the Bible, the book of Revelation, and was written sometime in the early 90’s.
We don’t exact date when each of the New Testament books were written, but we can be confident all the books of the New Testament were written in a span of about 50 years. The New Testament was finished before the end of the first century A.D., within 70 years of Jesus death. Each book was written by an apostle (someone who was directly called by Jesus, trained by Him, given special spiritual gifts and sent out by Him to preach Christ to the world), or a close associate of an apostle under apostolic supervision (like Luke and Mark). Every book of the New Testament was written by men who were under the direct control and guidance of the Holy Spirit. We can trust the books of the New Testament as reliable and accurate because they are eye witness accounts of Jesus’ life and teachings. Most significantly, every book of the New Testament is trustworthy because every book was written by men who were guided by the Holy Spirit of God to write the very words of God.