Nice words from the old Marburger against Jesus mythicism:
Of course the doubt as to whether Jesus really existed in unfounded and not worth refutation. No sane person can doubt that Jesus stands as founder behind the historical movement whose first distinct stage is represented by the oldest Palestinian community. But how far that community preserved an objectively true picture of him and his message is another question.
Bultmann, Jesus and the Word, pp. 17-18.