The Jesus We'll Never Know
One more level needs to be observed: the church has amplified its understanding of "Jesus," because it has interpreted Jesus in light of theological concerns. Let us refer to this Jesus as the "orthodox Jesus," the second person of the Trinity, God from God and Light from Light.
But the historical Jesus is someone or something else. The historical Jesus is the Jesus whom scholars have reconstructed on the basis of historical methods over against the canonical portraits of Jesus in the Gospels of our New Testament, and over against the orthodox Jesus of the church. The historical Jesus is more like the Jewish Jesus than the canonical Jesus or the orthodox Jesus. Drawing distinctions between these various Jesuses is important in order to understand what has happened in the contemporary academic scene.
First, the historical Jesus is the Jesus whom scholars reconstruct on the basis of historical methods. Scholars differ, so reconstructions differ. Furthermore, the methods that scholars use differ, so the reconstructions differ all the more. But this must be said: Most historical Jesus scholars assume that the Gospels are historically unreliable; thus, as a matter of discipline, they assess the Gospels to see if the evidence is sound. They do this by using methods common to all historical work but that are uniquely shaped by historical Jesus studies. The essential criterion used in most historical Jesus studies is called "double dissimilarity." Even though it is riddled with holes, this method is still used by many historical Jesus scholars.
According to the criterion of double dissimilarity, the only sayings or actions of Jesus that can be trusted are those that are dissimilar to both Judaism at the time of Jesus and to the beliefs of the earliest Christians immediately after Jesus. One of the most noteworthy examples is Jesus' characteristically calling God Abba, a title for God rarely found in Judaism or in earliest Christianity.
This example, though, is problematic from the get-go: Abba (an affectionate term for "Father," something akin to "Daddy") is in fact not genuinely doubly dissimilar, for it is found in Judaism, if rarely, as well as in Aramaic in the New Testament; moreover, the word Father is found everywhere. But, historical exceptions aside, that Jesus called God Abba won the day as a historically reliable attribute, and therefore won the hearts of all historical Jesus scholars.
Other criteria were developed, criticized, dropped, and modified, but all have this in common: Historical Jesus scholars reconstruct what Jesus was like by using historical methods to determine what in the Gospels can be trusted.
Second, the word reconstruct needs more attention. Most historical Jesus scholars assume that the Gospels have overcooked their portrait of Jesus, and that the church's Trinitarian theology wildly exceeds anything Jesus thought about himself and anything the evangelists believed. These scholars pursue a Jesus who is less than or different from or more primitive than what the Gospels teach and the church believes. There is no reason to do historical Jesus studies—to probe "what Jesus was really like"—if the Gospels are accurate and the church's beliefs are justified. There are only two reasons to engage in historical Jesus studies: first, to see if the church got him right; and second, if the church did not, to find the Jesus who is more authentic than the church's Jesus.