My previous discussion of Tacitus and Josephus concluded with the observation that the execution of Jesus under the Roman prefect Pontius Pilate is one of the most secure things we can know about the peasant from Nazareth with a high degree of probability using modern historical methods. This is because reference to the execution is attested in multiple, independent sources (criterion of multiple, independent attestation), including sources which refer to Jesus only incidentally, as an aside. Historical methods are limited in what they can reveal to us, particularly in the case of ancient history and especially in the case of studying an obscure Galilean villager who lived two thousand years ago (our knowledge of Galilee is quite limited, let alone our knowledge of an individual living there). When historical approaches can reveal something to us, it is only with certain levels of likelihood or probability, not certainty or “truth.” So cases of “high probability” that x or y happened are the best you can get in doing history (in the modern sense).
(Joachim Patenier, The Baptism of Christ [1515; Kunsthistorisches Museum, Vienna])
A second highly probable thing about Jesus accessible through historical methods is his immersion or baptism by John the Baptist. Scholars of early Christianity have developed a set of criteria for establishing the historical “authenticity” of particular activities or sayings attributed to Jesus in our sources, and multiple attestation is an important one. Another is known as the criterion of embarrassment. The principle here is: if a source reports some incident or saying even though the author of that source was hesitant about reporting it and somewhat embarrassed by the incident or saying, that author is not likely to have completely made up that incident or saying. On the other hand, the author in question could have simply omitted it to avoid any difficulty. In other words, when our sources report something in a round about way that reveals some embarrassment, there is a higher likelihood that it actually did happen.
One of the most illustrative cases in which this criterion plays a key role relates to the immersion of Jesus by John the Baptizer. The actual incident of Jesus being baptized in this case is attested in the gospel of Mark and in both Matthew and Luke. However, if one is using the two-source hypothesis, this would entail only one independent source for the incident, since Matthew and Luke are here drawing their material from Mark, the earliest ancient biography of Jesus. The Gospel of John completely omits the baptism itself and the Q-sayings source may or may not have included the actual baptism (Q did have material about John the Baptist and Jesus interacting). The so-called Gospel of the Hebrews and Gospel of the Nazoreans each report the immersion, so they may or may not (depending on their reliance on the synoptic traditions) supply further independent attestation. So the criterion of multiple attestation is not much help here.
This is where evidence of embarrassment comes in handy for the historian. The way that New Testament scholars explain this is that the embarrassment arises from the implications of a superior teacher or mentor in relation to an inferior student or protégé. At the time when the authors of the synoptics were writing (late first century) there were apparently still groups of followers of John the Baptizer (cf. Acts 19:1-7), which might raise the question: why not join a movement devoted to the superior baptizer rather the inferior baptized one. An early follower of Jesus might be concerned to assert that Jesus is superior to John the Baptist, even though Jesus’ baptism by John might imply otherwise.
Each of the gospels deals with this in different ways. The earliest, Mark, presents a saying in which John explicitly identifies his inferiority to Jesus, in terms of not being worthy to even undo Jesus’ sandals, and a dove, interpreted as the Spirit, confirms Jesus special status (Mk 1:7-11). Mathew uses Mark but adds in a further interchange in which John tries to prevent Jesus from being baptized by him, which would imply Jesus’ inferiority, but Jesus gives the green-light in terms of “fulfilling righteousness” (Mt 3:13-15). Luke goes about dealing with the embarrassment in an interesting way. Mark, Luke’s source, has that Jesus was “baptized by John in the Jordan” but Luke takes out John here and changes the phraseology so that there’s an ambiguity about who exactly baptized Jesus: “when Jesus also had been baptized… ” (Lk 3:21-22).
Finally, the Gospel of John (1:29-34) is usually out in left-field in comparison to the synoptic gospels, but the material on John the Baptist and Jesus is one of the very few cross-overs. How does the author of the gospel of John show what scholars call “embarrassment” here? The gospel of John omits the baptism of Jesus altogether but still presents John’s proclamations about the superiority of Jesus (e.g. the “Lamb of God” that takes away the sins of the world) and the descent of the dove indicating Jesus’ special status.
So all of our sources for the relation between John the Baptist and Jesus reveal what could be called an embarrassment at the implications of the baptism itself, one gospel to the point of omitting the immersion altogether. Mark, Matthew, and Luke could have likewise simply omitted this incident to avoid having to explain, but they included it despite their embarrassment. It is highly unlikely that the authors of these sources made up the baptism, and in historical terms it is highly probable that Jesus was actually baptized by John the Baptist. There are important corollaries of this piece of information, particularly relating to the apocalyptic worldview of John the Baptist, but I’ll have to save those for another post.