While John's tradition is pervasively autonomous and independent of the Synoptics, the Johannine tradition shows evidence of engagement with various aspects of the Synoptic Gospels and traditions. Multiple non-identical similarities with Mark suggest an 'interfluential' set of relationships between the preMarkan and the early Johannine tradition. At least three dozen times Luke departs from Mark and sides with John, suggesting that Luke has drawn from the Johannine tradition, probably within John's oral stages of development. Even Q shows evidence of Johannine influence, and this fact demands investigation. Matthean and Johannine traditions appear to have engaged similar issues related to their local Jewish communities, and they also evidence an intramural set of discussions regarding the emergence of structure and matters of egalitarian and Spirit-based aspects of leadership. Within this theory of John's relation to the Synoptics, John's tradition is assumed to have been both early and late. While John's tradition appears to be finalized latest among the Gospels, it is neither derivative from alien (non-Johannine) sources nor any of the Synoptic traditions. Rather, the Fourth Gospel represents an independent reflection upon the ministry of Jesus produced in at least two editions, and these factors will be drawn together in suggesting an overall theory of Johannine-Synoptic relations.
Anderson, Paul N., "Interfluential, Formative, and Dialectical - A Theory of John's Relation to the Synoptics (Part III of The Fourth Gospel and the Quest for Jesus: Modern Foundations Reconsidered)" (2006). Faculty Publications - College of Christian Studies. 273.