[T]he trend in Johannine studies has passed through an interesting cycle. At the end of the last century [the 19th century] and in the early years of this century [the 20th century], scholarship went through a period of extreme skepticism about this Gospel. John was dated very late, even to the second half of the 2nd century. As a product of the Hellenistic world, it was thought to be totally devoid of historical value and to have little relation to the Palestine of Jesus of Nazareth. The small kernel of fact in its pages was supposedly taken from the synoptic Gospels which served as the basis for the author’s elaborations. Needless to say, few critics thought that the Gospel according to John had the slightest connection with John son of Zebedee.
Some of these skeptical positions, especially those regarding authorship and the source of influence on the Gospel, are still maintained by many reputable scholars. Nevertheless, there is not one such position that has not been affected by a series of unexpected archaeological, documentary, and textual discoveries. These discoveries have led us to challenge intelligently the critical views that had almost become orthodox and to recognize how fragile was the base which supported the highly skeptical analysis of John. Consequently, since the Second World War there has emerged what Bishop John A. T. Robinson calls a "new look" in Johannine studies – a new look that shares much with the look once traditional in Christianity.
-Raymond E. Brown in his introduction to The Gospel According to John I-XII (Yale University Press 1995).