The other theory explains the need for continuation of the Mysteries under the guise of new solar cult we now know as Christianity, which was in the beginning completely heretical when compared to established official version by Constantine. Original Christianity was more related to Platonism, hermetism, Kabbalah and gnosticism and other philosophies belonging to pagan traditions and schools. Later these connections were denied and were carefully hidden by those of early clergy initiated in pagan Mysteries. So, in any case, both pagan religion an pagan Mystery schools were enlivened and continued by the Revelations, but to only those with ears to hear.
As for number SEVEN, this is so profound subject that the attempt to explain it in a short thread would be a Great Work indeed!