Community Hypothesis

Contrary to a widespread view, none of the four Gospels was written only for one particular community; far less do they simply reproduce the views of one individual community. They give primarily the views of their authors. We cannot even say with certainty whether they ever came into being only in one community, for the missionaries of the early church traveled a great deal and could be authoritative teachers at different places. So we should stop talking automatically about 'the community of Mark', 'of Luke', 'of Matthew', 'of John' as the one really responsible for the composition of a Gospel writing and its theology. The four Gospels have nothing to do with 'letters' which were occasioned by a community. These are relatively rare in the New Testament and its environment. Even more nonsensical is the term 'Q community', i.e. the community of the Logia source (we do not even really know in what forms this source [or these sources] existed). The authors of these works do not represent the view of a collective community, but of an individual yet authoritative teacher of one or more communities (or a school), and in their quite different forms proclaim the one truth which should be binding on all believers. This is true regardless of the fact that of course authors were in constant dialogue with a community, or more frequently several communities, and with their disciples or school.

Martin Hengel, The Four Gospels and the One Gospel of Jesus Christ, pg. 106-107