Paul Tillich’s discussion of historical Jesus research in volume 2 of his Systematic Theology is a minor tour de force and could still apply today without too much change. The problem of historical Jesus research, Tillich says, is that you can’t get “behind” the New Testament documents to the “real” historical Jesus of Nazareth because the records we have were shaped in very fundamental ways by the authors’ conviction that Jesus was the Christ. And any overall “portrait” of the historical Jesus is likely to be heavily dependent on which specific facts about or sayings of Jesus one takes to be historical. (For example, if one thinks that the historical Jesus applied the title “Son of Man” to himself, this will have a big effect on one’s overall picture of him.) Historical research can, at best, provide statements of greater or lesser probability. As Tillich notes bluntly, “The search for the historical Jesus was an attempt to discover a minimum of reliable facts about the man Jesus of Nazareth, in order to provide a safe foundation for the Christian faith. This attempt was a failure” (p. 105).
One attempt to get around this was to shift the focus away from the facts about Jesus and onto his words, or teachings. This was done in one of two ways. First, they can be regarded as general moral truths or insights into human nature. “As such, they belong to law, prophecy, or Wisdom literature such as is found in the Old Testament. They may transcend all three categories in terms of depth and power; but they do not transcend them in terms of character” (pp. 105-6). The second, “more profound” approach is to focus on Jesus’ announcement of the imminent arrival of the Kingdom of God. This is not a set of general rules, but a “concrete demand,” and the proper response is to decide for the Kingdom.
The problem with both approaches, Tillich says, is that neither one addresses the existential predicament of human beings–our estrangement from God. This isn’t something we can overcome through our own efforts. What we need is not a new law or a new set of teachings, but a new form of existence:
But neither method can answer the question of wherein lies the power to obey the teachings of Jesus or to make the decision for the Kingdom of God. This these methods cannot do because the answer must come from a new reality, which, according to the Christian message, is the New Being in Jesus as the Christ. The Cross is the symbol of a gift before it is the symbol of a demand. But, if this is accepted, it is impossible to retreat from the being of the Christ to his words. The last avenue of the search for the historical Jesus is barred, and the failure of the attempt to give a foundation to the Christian faith through historical research becomes obvious. (p. 106)
The only foundation for Christian faith, Tillich argues, is “the appearance of that reality which has created the faith” (p. 114).
This reality is the New Being, who conquers existential estrangement and thereby makes faith possible. This alone faith is able to guarantee–and that because its own existence is identical with the presence of the New Being. Faith itself is the immediate (not mediated by conclusions) evidence of the New Being within and under the conditions of existence. Precisely that is guaranteed by the very nature of the Christian faith. No historical criticism can question the immediate awareness of those who find themselves transformed into the state of faith. (p. 114)
In other words, the experience of the “New Being”–Tillich’s term for the state of overcoming the forces of sin and estrangement–is itself its own warrant. It requires no outside justification.
But surely this has something to do with Jesus? Otherwise, what makes this specifically Christian? Tillich says that the “power which has created and preserved the community of the New Being is not an abstract statement about its appearance; it is the picture of him in whom it has appeared (p. 114). Specifically he means the picture of Jesus in the New Testament. This isn’t an “empirically factual” portrait like the one a historian might attempt. It is the record of the impact Jesus had on those who first encountered and were transformed by him. Tillich says there is an “analogy between the picture and the actual personal life from which it has arisen”:
It was this reality, when encountered by the disciples, which created the picture. And it was, and still is, this picture which mediates the transforming power of the New Being. One can compare the analogia imaginis suggested here with the analogia entis–not as a method of knowing God but as a way (actually the only way) of speaking of God. In both cases it is impossible to push behind the analogy and to state directly what can be stated only indirectly, that is, symbolically in the knowledge of God and mediated through faith in the knowledge of Jesus. But this indirect, symbolic, and mediated character of our knowledge does not diminish its truth-value. For in both cases what is given to us as material for our indirect knowledge is dependent on the object of our knowledge. The symbolic material through which we speak about God is an expression of the divine self-manifestation, and the mediated material which is given to us in the biblical picture of the Christ is the result of the reception of the New Being and its transforming power on the part of the first witnesses. The concrete biblical material is not guaranteed by faith in respect to empirical factuality; but it is guaranteed as an adequate expression of the transforming power of the New Being in Jesus as the Christ. (p. 115)
Just as the symbols we use about God can mediate God’s self-manifestation, the picture of Christ in the New Testament can mediate the “New Being” of which he is the bearer. The only possible validation of this is the experience of being transformed. The proof of the pudding is in the eating, as it were.
The positions Tillich criticized live on in contemporary Christianity. More conservative Christians sometimes use historical research as a basis of apologetics, on the assumption that establishing certain historical facts about Jesus can prove, or at least provide warrant for, theological claims. On the other side of the spectrum, more liberal or progressive Christians sometimes try to identify a core set of “teachings of Jesus” that can be detached from the claims the New Testament makes about his status as the Christ. Tillich would argue that both of these approaches are doomed to failure because they try to build faith on varying degrees of historical probability.