Oral gospel traditions called the M source for Matthew and the L source for Luke, which may have been a mix of written and oral material (see Two-source hypothesis). Most scholars believe that the author of John's gospel used oral and written sources different from those available to the Synoptic authors – a "signs" source, a "revelatory discourse" source, and others – although there are indications that a later editor of this gospel may have used Mark and Luke. Oral transmission may also be seen as a different approach to understanding the Synoptic Gospels in New Testament scholarship. Current theories attempt to link
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