Short answers, pulled from the story.
The phrase New Testament first appeared in a written work by Tertullian around the year 208 AD. He used the Latin term testamentum to describe a collection of Christian scriptures that completed the older covenant found in Jewish writings.
A standard New Testament contains twenty-seven books divided into four main categories including gospels, historical narratives, letters, and apocalyptic visions. Four narrative accounts known as gospels tell the story of Jesus of Nazareth while thirteen letters attributed to Paul address specific communities facing internal conflicts or external pressures from pagan society.
Modern scholarship generally agrees that most New Testament authors remain anonymous despite traditional attributions. The names attached to the gospels emerged only by the mid-second century AD through church tradition rather than explicit claims inside the texts themselves.
Internal evidence points to 1 Thessalonians as likely the earliest letter written around 52 AD. Some scholars date many or all books before 70 AD while others place them significantly later in the second century.
Athanasius, Bishop of Alexandria, issued a Festal Letter in 367 listing exactly the books that would become the standard New Testament. The Synod of Hippo Regius in North Africa met in 393 AD to accept this list while the Council of Carthage confirmed it in 397 and 419 AD.
Bruce Metzger notes that over 5,800 Greek manuscripts exist alongside 10,000 Latin copies and thousands more in other ancient tongues. Even if original Greek versions were lost scholars could reconstruct the entire New Testament using only these surviving translations and early church quotations.