The significance of Pannenberg and Cullmann is in their showing that the Enlightenment's emphasis on critical thinking is not unspiritual and antithetical to faith. The problem with the philosophy of the Enlightenment was that it was not critical enough, for it failed to be self-critical and to recognize its own naturalistic presuppositions.
Faith and knowledge, while distinct, are inseparable. To know the truth in any field of knowledge requires the personal interest of the scholar in his subject along with a critical awareness of his assumptions (beliefs). This is no less true for the critical historian who seeks to examine the historicity of Jesus' resurrection from the dead. Pannenberg writes:
Anyone who will not trust himself to the God revealed in Jesus' resurrection will also obscure for himself any recognition of the history which reveals God, even if he once possessed it. For no one could clearly recognize God's divinity and love and yet persist in refusing to trust him. And so in fact only believers hold fast to the recognition of God's revelation in Jesus' resurrection.Wolfhart Pannenberg, Faith and Reality (Philadelphia: Westminster, 1977), 66-67.
Intellectual insight and trust are mutually related. Only from the standpoint of the faith of those who participate in the New Creation can we have the eyes to see and the mind to know the truth of the gospel of Jesus Christ. And only from the standpoint of the mind's insight that Jesus is Lord can we come to believe in him.
The synthesis of critical thinking of the Enlightenment and the development of a systematic/ontological worldview typical of the classical creeds of the church is biblically and theologically necessary if we wish to make the biblical revelation intelligible today. For if we are to speak of truth in reference to the Bible, we are not permitted to redefine the contents of the Bible in a gnostic manner as if its truth were a blind affirmation inaccessible to rational reflection. And if the content of the Bible is available for rational interpretation, then its truth can be framed into an intelligible worldview. In this way, both the epistemological emphasis of the Enlightenment and the ontological emphasis of the premodern world can be brought together for the development and deepening of our faith and understanding of God's revelation.