Gospel of Thomas in the late 2nd century that "since there are four quarters of the earth ... it is fitting that the church should have four pillars ... the four Gospels" ("Against Heresies", 3.11.8), and then shortly thereafter made the first known quotation from a fourth gospel—the canonical version of the Gospel of John. The late 2nd-century Muratorian fragment also recognizes only the three synoptic gospels and John. Bible scholar Bruce Metzger wrote regarding the formation of the New Testament canon, "Although the fringes of the emerging canon remained unsettled for generations, a high degree of unanimity concerning the greater part of
New Testament are most often part of an established lectionary (i.e., selected texts to be read at church services on specific days), and (together with an Old Testament reading and a Psalm) include a non-gospel reading from the New Testament and culminate with a Gospel reading. No readings from the Book of Revelation, however, are included in the standard lectionary of the Eastern Orthodox churches. Central to the Christian liturgy is the celebration of the Eucharist or "Holy Communion". The Words of Institution that begin this rite are drawn directly from 1 Corinthians 11:23–26. In addition, the communal recitation of the Lord's