In New Testament textual criticism, a broad consensus has emerged that the Markan shorter ending, the scene of Jesus' agony (Luke 22:43–44), and the story of the adulterous woman (John 7:53–8:11) did not originally belong to the text of the Gospels. Because the traditions underlying these passages are early, the most recent critical editions of the Greek New Testament print them in the main text. On the basis of an analysis of these early traditions, the present study contends that (1) the conclusio brevior was appended to the Gospel according to Mark as part of the Vorlage for the earliest known Old Latin translation; (2) the Agonia Christi was inserted into the "Western text" of Luke's Gospel as an anti-Gnostic polemic; and (3) the Pericope Adulterae was incorporated into John as an anti-Novatianist polemical discourse via the Greek exemplars underlying the Vulgate.