"Criticism of Jesus research methods
A number of scholars have criticised Historical Jesus research for religious bias and lack of methodological soundness, and some have argued that modern biblical scholarship is insufficiently critical and sometimes amounts to covert apologetics.
John Meier, a Catholic priest and a professor of theology at University of Notre Dame, has stated "... I think a lot of the confusion comes from the fact that people claim they are doing a quest for the historical Jesus when de facto they’re doing theology, albeit a theology that is indeed historically informed ..." Meier also wrote that in the past the quest for the historical Jesus has often been motivated more by a desire to produce an alternate Christology than a true historical search.
The British Methodist scholar Clive Marsh has stated that the construction of the portraits of Jesus as part of various quests have often been driven by "specific agendas" and that historical components of the relevant biblical texts are often interpreted to fit specific goals. Marsh lists theological agendas that aim to confirm the divinity of Jesus, anti-ecclesiastical agendas that aim to discredit Christianity and political agendas that aim to interpret the teachings of Jesus with the hope of causing social change.
The New Testament scholar Nicholas Perrin has argued that since most biblical scholars are Christians, a certain bias is inevitable, but he does not see this as a major problem.
Lack of methodological soundness
The historical analysis techniques used by biblical scholars have been questioned, and according to James Dunn it is not possible "to construct (from the available data) a Jesus who will be the real Jesus."
W.R. Herzog has stated that "What we call the historical Jesus is the composite of the recoverable bits and pieces of historical information and speculation about him that we assemble, construct, and reconstruct. For this reason, the historical Jesus is, in Meier's words, 'a modern abstraction and construct.'"
Donald Akenson, Professor of Irish Studies in the department of history at Queen's University has argued that, with very few exceptions, the historians attempting to reconstruct a biography of the man apart from the mere facts of his existence and crucifixion have not followed sound historical practices. He has stated that there is an unhealthy reliance on consensus, for propositions, which should otherwise be based on primary sources, or rigorous interpretation. He also identifies a peculiar downward dating creep, and holds that some of the criteria being used are faulty. He says that the overwhelming majority of biblical scholars are employed in institutions whose roots are in religious beliefs. Because of this, more than any other group in present-day academia, biblical historians are under immense pressure to theologize their historical work. It is only through considerable individual heroism, that many biblical historians have managed to maintain the scholarly integrity of their work.
Dale Allison, a Presbyterian theologian and professor of New Testament Exegesis and Early Christianity at Pittsburgh Theological Seminary, says, "... We wield our criteria to get what we want ..."
According to James Dunn, "...the 'historical Jesus' is properly speaking a nineteenth- and twentieth-century construction using the data provided by the Synoptic tradition, not Jesus back then and not a figure in history." (Emphasis in the original). Dunn further explains that "the facts are not to be identified as data; they are always an interpretation of the data.
Since Albert Schweitzer's book The Quest of the Historical Jesus, scholars have for long stated that many of the portraits of Jesus are "pale reflections of the researchers" themselves. Albert Schweitzer accused early scholars of religious bias. John Dominic Crossan summarized the recent situation by stating that many authors writing about the life of Jesus "... do autobiography and call it biography."
Scarcity of sources
Bart Ehrman and separately Andreas Köstenberger contend that given the scarcity of historical sources, it is generally difficult for any scholar to construct a portrait of Jesus that can be considered historically valid beyond the basic elements of his life. On the other hand, scholars such as N. T. Wright and Luke Timothy Johnson argue that the image of Jesus presented in the gospels is largely accurate, and that dissenting scholars are simply too cautious about what we can claim to know about the ancient era."