The Gospel of LUKE - the only Gospel written by a Gentile.... If you were to judge book length based on the number of chapters, you'd walk away thinking that Matthew and Acts are longer than Luke. After all, they both have 28 chapters and Luke's Gospel only contains 24. But with a word count of 19,482, Luke's is actually the longest. Acts has 18,450 Greek words, while Matthew's contains 18,346. In fact, even though Paul wrote the most books in the New Testament (13) followed by John (5), Luke is actually the New Testament's most prolific author by sheer volume.