<P> Collections of related texts such as letters of the Apostle Paul ( a major collection of which must have been made already by the early 2nd century ) and the Canonical Gospels of Matthew , Mark , Luke , and John ( asserted by Irenaeus of Lyon in the late - 2nd century as the Four Gospels ) gradually were joined to other collections and single works in different combinations to form various Christian canons of Scripture . Over time , some disputed books , such as the Book of Revelation and the Minor Catholic ( General ) Epistles were introduced into canons in which they were originally absent . Other works earlier held to be Scripture , such as 1 Clement , the Shepherd of Hermas , and the Diatessaron , were excluded from the New Testament . The Old Testament canon is not completely uniform among all major Christian groups including Roman Catholics , Protestants , the Greek Orthodox Church , the Slavic Orthodox Churches , and the Armenian Orthodox Church . However , the twenty - seven - book canon of the New Testament , at least since Late Antiquity , has been almost universally recognized within Christianity ( see Development of the New Testament canon ) . </P>
<P> Collections of related texts such as letters of the Apostle Paul ( a major collection of which must have been made already by the early 2nd century ) and the Canonical Gospels of Matthew , Mark , Luke , and John ( asserted by Irenaeus of Lyon in the late - 2nd century as the Four Gospels ) gradually were joined to other collections and single works in different combinations to form various Christian canons of Scripture . Over time , some disputed books , such as the Book of Revelation and the Minor Catholic ( General ) Epistles were introduced into canons in which they were originally absent . Other works earlier held to be Scripture , such as 1 Clement , the Shepherd of Hermas , and the Diatessaron , were excluded from the New Testament . The Old Testament canon is not completely uniform among all major Christian groups including Roman Catholics , Protestants , the Greek Orthodox Church , the Slavic Orthodox Churches , and the Armenian Orthodox Church . However , the twenty - seven - book canon of the New Testament , at least since Late Antiquity , has been almost universally recognized within Christianity ( see Development of the New Testament canon ) . </P>
who wrote the 21 letters in the new testament
who wrote the 21 letters in the new testament
Apostle Paul
Apostle Paul