Paul Tillich was one Christian theologian who made extensive use of existentialist ideas, but in his case he relied more upon Martin Heidegger than Søren Kierkegaard. For example, Tillich used Heidegger’s concept of “Being,” but unlike Heidegger he argued that God is “Being-itself,” which is to say our ability to overcome doubt and anxiety in order to make the necessary choices to commit ourselves to a way of living.
This “God” is not the traditional God of classical, philosophical theism nor is it the God of traditional Christian theology — a sharp contrast to Barth’s position, which has been labeled “neo-orthodoxy” because of its call for us to return to a a non-rational faith. Tillich’s theological message was not about turning our lives over to the will of a divine power but rather that it is possible for us to overcome the apparent meaninglessness and emptiness of our lives. That, however, could only be achieved through what we choose to do in response to that meaninglessness.
Perhaps the most extensive developments of existentialist themes for Christian theology can be found in the work of Rudolf Bultmann, a theologian who argued that the New Testament conveys a genuinely existentialist message which has been lost and/or covered over through the years. What we need to learn from the text is the idea that we have to choose between living an “authentic” existence (where we face up to our own limits, including our mortality) and an “inauthentic” existence (where we recoil from despair and mortality).
Bultmann, like Tillich, relied heavily upon the writings of Martin Heidegger — so much so, in fact, that critics have charged that Bultmann simply portrays Jesus Christ as a precursor to Heidegger. There is some merit to this accusation. Although Bultmann argued that the choice between an authentic and inauthentic existence cannot be made on rational grounds, there there does not seem to be a strong argument for saying that this is somehow analogous to the concept of Christian grace.
Evangelical Protestantism today owes a great deal to the early developments of Christian existentialism — but probably more those of Barth than of Tillich and Bultmann. We continue to see a focus on key themes like the the emphasis of an engagement with the Bible rather than philosophers, the importance of a personal crisis with leads one to a deeper faith and personal understanding of God, and valuation of irrational faith over and above any attempt to understand God through reason or intellect.
This is a rather ironic situation because existentialism is most often associated with atheism and nihilism, two positions which are common excoriated by evangelicals. They simply don’t realize that they share more in common with at least some atheists and atheistic existentialists than they realize — a problem that might be corrected if they were to take the time to study the history of existentialism more closely.
