Wrede's Messianic Secret: Introduction 1.1
1.) Although it should be taken as axiomatic that what lies before the historian examining the gospels is a "later narrator's conception of Jesus' life and that this conception is not identical with the thing itself" (p.5) scholars often recall this axiom only when they discover strong miraculous features in a text, or when contradictions arise within the same source of a text, or when separate reports clash with one another. This means that unless one of these three features occurs scholars, according to Wrede, are inclined too quickly to proceed with their historical assessment of the gospels as if what is before them is generally historically accurate.
2.) Scholars in their haste to utilize the gospel accounts for composing a historical portrait of Jesus too quickly pass over the evangelists' literary presentations of those accounts. What inevitably results from this is that "something which was not in the writers' mind is substituted for the account and represented as its historical content" (p 5). This neglect of what the narrator is trying to convey by his narration means that scholars will inevitably gloss over important bits of information in the gospel texts.
3.) Though psychology has a place within historical Jesus research it is widely abused by scholars: "The scientific study of the life of Jesus is suffering from psychological 'suppositionitis' which amounts to a sort of historical guess work. For this reason interpretations to suit every taste proliferate." (p 6). Furthermore, says Wrede, for psycho-analyses to provide a valuable contribution to Jesus research it must have lucid facts concerning Jesus with which to work. Unfortunately, however, too many things about Jesus are historically uncertain and thus for this reason psycho-analyses need to be used sparringly.
To summarize, Wrede's beef with the scholarship of his day derives from scholars not approaching the gospels with enough healthy skepticism, and it is this lack of skepticism that results in premature conclusions being made concerning the historical figure of Jesus.