What is the earliest book written in the New Testament?

Galatians, written around 48-49 A.D. by Paul, is widely considered the earliest book of the New Testament. Also, Thessalonians 1, written by Paul around 50 A.D. is considered to be one of the earliest books of the New Testament (and some scholars consider it to be the earliest).

Paul's letters are likely the earliest writings included in the New Testament.

The synoptic gospels, Matthew, Mark, and Luke are considered to have been written shortly after 70 A.D. when the Jewish Temple was destroyed by the Romans. Mark is considered by many to have been written first with Matthew and Luke expanding upon his work, although a few scholars agree with Christian tradition which places Matthew as the first gospel written.

Revelations is most likely the last book of the New Testament, not only in terms of the order in which it appears, but also in terms of its proposed dating.

Answer

Galatians was the earliest book, written in 49AD.

Order of Books written in New Testament

Galatians 49

AD

James 50

Thessalonians 51; 52

Corinthinians 55; 57

Romans 57

Matthew late 50's -early 60's

Mark late 50's -early 60's

Luke 60-61

Ephesians 61

Colossians 61

Philemon 61

Phili[ppians 62

Acts 63

1 Timothy 63

Hebrews 64

John 65

Titus 65

1, 2, 3, John 65

1 Peter 65

2 Timothy 67

2 Peter 67

Jude 68

(last] Revelation 70

Above are definite dates taken from "The Untold Story of the New Tstament Church" by Frank Viola

ISBN 0-7684-2236-1. [The book is presently unavailable for downloading].