http://www.earlychristianwritings.com/schweitzer/The German theologian Schweitzer, writing before WWI, intends his work as a contribution to Christian theology -- and particular on the efforts up to his time to allow scientific and historical reflection on the data, such as it is (and Schweitzer says clearly "From these materials we can only get a Life of Jesus with yawning gaps"), to inform faith.
Here is a sample from early in the work:
The critical study of the life of Jesus has been for theology a school of honesty. The world had never seen before, and will never see again, a struggle for truth so full of pain and renunciation as that of which the Lives of Jesus of the last hundred years contain the cryptic record. One must lead the successive Lives of Jesus with which Hase followed the course of the study from the 'twenties to the 'seventies of the nineteenth century to get an inkling of what it must have cost the men who lived through that decisive period really to maintain that 'courageous freedom of investigation' which the great Jena professor, in the preface to his first Life of Jesus, claims for his researches. One sees in him the marks of the struggle with which he gives up, bit by bit, things which, when he wrote that preface, he never dreamed he would have to surrender. It was fortunate for these men that their sympathies sometimes obscured their critical vision, so that, without becoming insincere, they were able to take white clouds for distant mountains. (The Quest of the Historical Jesus)
And from Chapter XX (Results):
There is nothing more negative than the result of the critical study of the Life of Jesus.
The Jesus of Nazareth who came forward publicly as the Messiah, who preached the ethic of the Kingdom of God, who founded the Kingdom of Heaven upon earth, and died to give His work its final consecration, never had any existence. He is a figure designed by rationalism, endowed with life by liberalism, and clothed by modern theology in an historical garb. (The Quest of the Historical Jesus)
I think that in a fundamental way, Schweitzer saw clearly what the dogmatists have never seen:
Jesus means something to our world because a mighty spiritual force streams forth from Him and flows through our time also. This fact can neither be shaken nor confirmed by any historical discovery. It is the solid foundation of Christianity.
The mistake was to suppose that Jesus could come to mean more to our time by entering into it as a man like ourselves. That is not possible. First because such a Jesus never existed. Secondly because, although historical knowledge can no doubt introduce greater clearness into an existing spiritual life, it cannot call spiritual life into existence. History can destroy the present; it can reconcile the present with the past; can even to a certain extent transport the present into the past; but to contribute to the making of the present is not given unto it. (The Quest of the Historical Jesus)
In holding up Schweitzer as a source, I do not intend to minimize certain subsequent objections to his work (as, for example, those based on the observation that he may have had certain racist or anti-semitic ideas): I do, however, want to say explicitly that he provided an early and clear statement of the modern view that essentially nothing definite can be said with any certainty regarding the life of Jesus of Nazareth and honest inspection reveals that whatever is claimed, to be definite, is essentially fictitious; thus modern Christianity must seek the basis for its faith in something other than historical evidence. Since Schweitzer's time, a few additional texts have been discovered, and archaeology as a science has made some progress, but these developments really make no significant difference to Schweitzer's conclusions. Additional intellectual techniques for analysis have been applied to the questions Schweitzer raised (notably, over several generations, the application of historical Marxist methods to the texts), which suggestively extract further information from the (limited) data, but Schweitzer's objections remain more or less unaffected.
And I personally find Schweitzer's subsequent effort to live the meaning of his Christianity in Africa (even if contaminated by his own ethnocentric heresies) profounding touching.
Albert Schweitzer
The Nobel Peace Prize 1952
Nobel Lecture, November 4, 1954
The Problem of Peace
... But the essential fact which we should acknowledge in our conscience, and which we should have acknowledged a long time ago, is that we are becoming inhuman to the extent that we become supermen. We have learned to tolerate the facts of war: that men are killed en masse -- some twenty million in the Second World War -- that whole cities and their inhabitants are annihilated by the atomic bomb, that men are turned into living torches by incendiary bombs. We learn of these things from the radio or newspapers and we judge them according to whether they signify success for the group of peoples to which we belong, or for our enemies. When we do admit to ourselves that such acts are the results of inhuman conduct, our admission is accompanied by the thought that the very fact of war itself leaves us no option but to accept them. In resigning ourselves to our fate without a struggle, we are guilty of inhumanity.
What really matters is that we should all of us realize that we are guilty of inhumanity. The horror of this realization should shake us out of our lethargy so that we can direct our hopes and our intentions to the coming of an era in which war will have no place ...
Is the spirit capable of achieving what we in our distress must expect of it?
Let us not underestimate its power, the evidence of which can be seen throughout the history of mankind. The spirit created this humanitarianism which is the origin of all progress toward some form of higher existence. Inspired by humanitarianism we are true to ourselves and capable of creating. Inspired by a contrary spirit we are unfaithful to ourselves and fall prey to all manner of error.
The height to which the spirit can ascend was revealed in the seventeenth and eighteenth centuries. It led those peoples of Europe who possessed it out of the Middle Ages, putting an end to superstition, witch hunts, torture, and a multitude of other forms of cruelty or traditional folly. It replaced the old with the new in an evolutionary way that never ceases to astonish those who observe it. All that we have ever possessed of true civilization, and indeed all that we still possess, can be traced to a manifestation of this spirit ...
http://nobelprize.org/nobel_prizes/peace/laureates/1952/schweitzer-lecture-e.html