It is not uncommon for people who study the Bible at degree level to be overwhelmed by the 'scientific' method of biblical studies they meet in the university. Some lose their faith, not because their faith was shown to be utterly devoid of value or sense, but because they did not recognise the assumptions behind what they were being taught in their degree program, and place these assumptions under scrutiny. Some leave utterly bewildered and lost, others retreat into literalism. Still others embrace the scientific method, recognising the sheer rationality of the 'science'. (The historical-critical method is a very powerful tool.) However, they too might miss the assumptions behind what they are being taught, possibly because they already hold similar assumptions! I'm thinking here, for example, of the assumption that God does not enter into our history from, in some real sense, outside it, and that everything must have a 'natural' cause (and only a natural cause) to be considered anything but superstition.
The historical-critical method, as it is called, is a great tool for understanding Scripture, but its practice can be laden with philosophical-theological assumptions that cannot be justified from the method itself. However, follow the trajectory of the assumptions and a practical atheism awaits. It is quite an experience to wake up one day and realise that you have been duped into just such a practical atheism. Again, if you have this experience of realising that you have been duped, don't trudge off to the (so-called) literalists, and don't give up your faith because, on the one hand, you can see the nihilism of a theology devoid of God's action in the world, but, on the other hand, don't know how to get God back. It is the assumptions behind the method that are critical here, not the historical-critical method itself. The assumptions I am thinking of here are utterly alien to the biblical worldview. The solution is to scrutinize them and replace them with a global view of Scripture arising from the text of Scripture itself. You are free not to believe the biblical faith, but at least then it will be the biblical faith that you are rejecting!
Here are three assumptions I have flirted with and now reject:
1. The Hidden Jesus of History (vs the Christ of Faith of the Church)
There are many people who allege that the church distorted the 'real Jesus' into a divine figure, and that this distortion is a massive accretion placed on top of the real Jesus. If the novice biblical interpreter hasn't done some work on the Enlightenment legacy in biblical studies s/he might be easily convinced by purveyors of this assumption that one must pierce the layers of tradition to grasp the 'real Jesus'. At worst Jesus becomes a figure shrouded in mystery and beyond our reach because the church's distortion of him is opaque to critical-historical examination.
So it is alleged that the accretions are in the New Testament itself, and are not merely a later layer of church doctrine poured over the top of a pristine history contained in the New Testament. The historical-critical method is used to free the 'original Jesus' and his message from this faith distortion. So practitioners of this assumption attempt to sieve out the later accretions of doctrine, liturgy and creed from the text through a variety of methods. For example, the more complex the theology of a text, or the more exalted Jesus appears, the more likely the real Jesus is waiting to be liberated from church doctrine and faith. (A sort of evolutionary theory transposed into biblical studies - i.e. complexity comes at the end of a long process of evolution. In this case, however, complex theology is to be avoided and, where possible, pierced for its historical kernel. ) Or, again, rather than the object of biblical study being God and Jesus, and the special relationship with God enjoyed by Jesus (a ubiquitous affirmation contained within the New Testament), the object of study becomes the faith of the communities that produced the text. The text then becomes a witness to the faith of these communities, unrelated to the Scriptural and faith claim of Jesus' identity with God. This is paralleled in the debates that attempt to drive a wedge between the Christ of faith and the Jesus of history, or between faith and reason, as if the two poles are utterly immiscible, leading to the priority of a certain kind of reason and a certain kind of history over a more unified view of faith, history and reason.
As an aside, I wonder if some of the blame for this can be laid at the feet of the Reformers. It is intriguing that the impetus in this movement splitting Jesus of History and Christ of Faith came from the Protestant Church, and makes one suspicious. The Protestant Reformers' reaction against the Roman Church of the day, formulated as an escape from ordinary religion to true faith through Sola Scriptura, is only a jump away (although a long jump admittedly) from seeing the need to make the same split in Scripture itself between faith and church dogma.
In summary, if it is assumed that God cannot be involved in history, or at least that we must limit ourselves to studying only that which is the result of natural causes alone, then the historical-critical method can be used to remove God from Scripture's presentation of the identity and work of Jesus. The result can be the 'Spongification' of Jesus, or talk only of the church's faith itself (not the Jesus and God attested in Scripture), or perhaps even Jesus' own experience of God, as a substitute for Scripture's affirmation of Jesus' special relationship with, indeed, his identity with, God.
2. History as a Solid State
The assumed homogeneity of history leads some interpreters of the Bible to discount anything that cannot be fitted into our current experience. (E.g. the resurrection of Jesus) But why can't God introduce the new and unique into history through history? The Bible says God can, and to interpret otherwise requires an alien assumption to be placed over the text. As Moltmann pointed out forty years ago, the theological conclusion to be drawn from the uniqueness of the resurrection of Jesus is not its dismissal, but making it the judge of our historical experience. I know that goes against Enlightenment assumptions, but that is the point. It is the Bible's way of ordering reality and it is different than a materialistic reading of history. The resurrection of Jesus is about the future made present, not its in/compatibility with the cul-de-sac of humanity's business as usual.
3. A Hellenized Christianity
While it is undoubtedly true that research into the Jewishness of Jesus and his culture (has and) will lead to many new insights, it is not clear that this should come from a divorce between the Jewish Jesus and the Graeco-Roman culture of his era. It has been popular to blame the Hellenization of Christianity for all the distortions of the simple Jew from Nazareth alleged to exist in the New Testament and later church liturgy and doctrine. De-Hellenization was all the rage for a century or more, directed both at Scripture and the early church period of the great councils of the church. It wasn't that long ago that students of the Bible might be taught that the 'Logos' mentioned in John's Gospel was a thoroughly Greek concept indebted to the Greek Philosophies of the age. Indeed, the alleged Hellenism of John's Gospel was evidence of its Gnostic character to many. Now it is recognised that Logos/Word has a thoroughly Hebraic history as well. In relation to the great councils of the early church and the creeds produced, the doctrine of the Trinity is anything but the Hellenization of Christianity. While the formal doctrine is couched in the philosophical language of Hellenism, it is not the end-product of the Hellenization of Christianity, but the defense and confirmation of the Gospel itself. The hierarchy of the gods of Hellenism was tipped on its side with the co-equality of the Eternal Father and Son, and later, Spirit. The eternal fatherhood of God safeguards the special relationship of Jesus with God witnessed to in Scripture.
All this is not to suggest that we should return to a pre-critical era. (The kind of scholarship represented in the work of N. T. Wright, Richard Bauckham, Benedict XVI, Hans Urs von Balthasar or Karl Barth is not pre-critical.) Rather, as a thought experiment attend to the Scriptures with the full arsenal of techniques of the historical-critical method minus the above prejudices. What is required is to attend to the text with an openness to see the correspondences between history and faith and the priority of God in the critical distance between the acts of God and our usual experience. If it is not assumed that Scripture's presentation of the unique relationship of Jesus with God is an alien overlay on the real Jesus, it is surprising to discover what the historical-critical method reveals about Jesus that is supportive of the faith of the church and yet not an offense to reason and historical study. (I will shortly post on a book that provides some interesting thoughts on John's presentation of the identity of Jesus with God.)