Christianity inherited this practice from Judaism. It is believed that in the time of Jesus in the land of Israel, there was a semiseptennial cycle of readings that covered the whole of the Torah (the five books of Moses) twice in seven years. Each weekly reading or seder was paired with a psalm and a reading from the prophets. The readings from the prophets reflected a fervent messianic expectation. It is possible that the ministry of Jesus covered one three-and-a-half year trip through the Torah, half of a semiseptennial cycle. Rob Wilson gives an introduction to the semiseptennial cycle here.
In my church community at Church of the Messiah (Xenia, Ohio), we have adopted a semiseptennial cycle, matching New Testament readings with 158 seders. We've gone through the first 3 and a half years and have started the second. This blog will chronicle our journey.
(Note from 2023: In our second round through the cycle, we expanded to 162 seders.)
