Although I do believe that Pannenberg gives too much weight to a Christology "from below," which insufficiently deals with the eternal logos, I very much appreciate this quote.
"If it cannot be shown that the proclamation about Christ has ‘support in the historical Jesus himself,’ then the proclamation must appear as a product of faith. ‘If the person to whom the kerygma refers is in no way concretely definable in his historicity, if the reference of the kerygma to Jesus consists exclusively in the assertions for whose understanding Jesus himself is irrelevant, as merely a cipher that is accidental and in itself says nothing, then the kerygma—if it then could be kerygma at all—would be pure myth."
 Wolfhart Pannenberg, Jesus—God and Man, trans. Lewis L. Wilkins and Duane A. Priebe (Philadelphia: Westminster Press, 1968), 27