Early in the second century the motives which had originally led certain Christians to write the four Gospels induced the Church to regard those books as the most authentic, and therefore authoritative, records of the life and teachings of the Master. We have no distinctive history of the process. It was gradual, and probably almost unconscious. The fact that three of the Gospels were associated with the names of apostles and the other with Luke, the faithful companion of Paul, undoubtedly tended to establish their authority; but the chief canonizing influence was the need of such records for private and public reading. The production, early in the second century, of spurious gospels, like the Gospel of Marcion, written to furnish a literary basis for certain heretical doctrines, also the desire of the Church Fathers to have records to which they could appeal as authoritative hastened the formation of the first New Testament canon. The use of the Gospels in the services of the church, which probably began before the close of the first Christian century, by degrees gave them an authority equal to that of the Old Testament Scriptures. The earliest canon consisted simply of these four books. They seem to have been universally accepted by the Western Church by the middle of the second century. About 152 A.D. Justin Martyr, in proving his positions, refers to the _Memoirs of the Apostles compiled by Christ's apostles and those who associated with them_, and during the same decade his pupil Tatian made his _Diatessaron_ by combining our present four Gospels. [Sidenote: _The second edition of the New Testament_] Meantime the natural desire to supplement the teachings of Jesus by those of the Apostles led the Church to single out certain of the epistles and associate them with the Gospels. Already in the first century the apostolic epistles and traditions were cherished by the individual churches to which they had been first directed. In time, however, the need for a written record of the apostolic teachings and work became widely felt. Hence, by the end of the second century, Acts and the thirteen Pauline epistles, First Peter, First John, and the Apocalypse, were by common consent placed side by side with the Gospels, at least by the leaders of the Western Church. [Sidenote: _The disputed books_] Regarding the authority of the remaining New Testament books, Hebrews, James, First and Second John, and Jude, opinion long remained undecided. Concerning them an earnest discussion was carried on for the next two centuries. By certain leaders in the Church they were regarded as authoritative, while elsewhere and at different periods, other books, like the Gospel to the Hebrews, the Epistle of Barnabas, Clement's Epistle to the Corinthians, the Shepherd of Hermas, and the Apocalypse of Peter, were included in the canon and even given the priority over the disputed books later included in our New Testament.