The demythologizing of the New Testament proclamation towards the middle of the 19.th century.
Rudolf Bultmanns History of the Synoptic Tradition (1921) is still highly regarded as an essential tool for gospel research, even by scholars who reject his analyses of the conventional rhetorical pericopes or narrative units of which the Gospels are assembled, and the historically-oriented principles called "form criticism" of which Bultmann has been the most influential exponent: "The aim of form-criticism is to determine the original form of a piece of narrative, a dominical saying or a parable. In the process we learn to distinguish secondary additions and forms, and these in turn lead to important results for the history of the tradition."
In 1941 he applied form criticism to the Gospel of John, in which he distinguished the presence of a lost Signs Gospel on which John, alone of the evangelists, depended. This monograph, highly controversial at the time, became a milestone in research into the historical Jesus. The same year his lecture New Testament and Mythology: The Problem of Demythologizing the New Testament Message called on interpreters to replace traditional supernaturalism with the temporal and existential categories of Bultmann's colleague, Martin Heidegger, rejecting doctrines such as the pre-existence of Christ.
Bultmann believed this endeavor would make accessible to modern audiences - already immersed in science and technology - the reality of Jesus' teachings. Bultmann thus understood the project of "demythologizing the New Testament proclamation" as an evangelical task, clarifying the kerygma, or gospel proclamation, by stripping it of elements of the first-century "mythical world picture" that had potential to alienate modern people from Christian faith: "It is impossible to repristinate a past world picture by sheer resolve, especially a mythical world picture, now that all of our thinking is irrevocably formed by science. A blind acceptance of New Testament mythology would be simply arbitrariness; to make such acceptance a demand of faith would be to reduce faith to a work"
While Bultmann reinterpreted theological language in existential terms, he nonetheless maintained that the New Testament proclaimed a message more radical than any modern existentialism. In both the boasting of legalists "who are faithful to the law," and the boasting of the philosophers "who are proud of their wisdom," Bultmann finds a "basic human attitude" of "highhandedness that tries to bring within our own power even the submission that we know to be our authentic being." Standing against all human highhandedness is the New Testament, "which claims that we can in no way free ourselves from our factual fallenness in the world but are freed from it only by an act of God ... the salvation occurrence that is realized in Christ."
Bultmann remained convinced the narratives of the life of Jesus were offering theology in story form. Lessons were taught in the familiar language of myth. They were not to be excluded, but given explanation so they could be understood for today. Bultmann thought faith should become a present day reality. To Bultmann, the people of the world appeared to be always in disappointment and turmoil. Faith must be a determined vital act of will, not a culling and extolling of "ancient proofs."