In the synagogue people heard scriptures read, taught, discussed, or expounded. The vast majority of first century people could not read. So people didn`t own bibles. The Jews had access to their sacred stories in the synagogue. The memory of the historical Jesus could have been recalled, restated, and passed in the synagogue. And the gospel stories may also be shaped in terms of Jewish liturgy. The crucifixion may be shaped against the passover. The transfiguration echoes Hanukkah. Many things are reminiscent of Rosh Hashanah.. So as it says in Acts, they would read from the Torah, then from the former prophets (Joshua through Kings), and finally from the latter prophets (Isaiah through Malachi). At that point the synagogue leader would ask if anyone would like to bring any message or experience that might illumine the readings. So followers of Jesus may have then recalled their memories of him which that Sabbath elicited. This could be where all the midrash/imitation/mixing is coming from. This is what Paul does in Acts (13:16b-41). They went through this process for about forty years before the gospels were written (Spong, Reclaiming the Bible for a Non-Religious World).