In “Attack of the Cybermen” the return of the show to its earliest roots is highlighted, not only by the Doctor’s emphatic statement, “This is the real me,” but also by the materialization of the TARDIS in a junkyard that looks familiar – one belonging to I. M. Foreman and located at 70 Totter’s Lane. The TARDIS, and the character of the Doctor, are in some ways back where they began. The episode proceeds to focus still more attention on the show’s original Doctor by harking back to the last William Hartnell episode, “The Tenth Planet.” In “Attack of the Cybermen” in fact the plan of the Cybermen is to rewrite history so as to prevent the things that happened in that episode – earlier in the Doctor’s life but still in the future from Earth’s perspective. They want to prevent the destruction of their home planet of Mondas.
As regards religion, two points are worth noting. One is the focus on Haley’s comet – on the one hand, comets being viewed as harbingers of doom by superstitious Earthlings, on the other, the Cybermen are planning to divert it and so disrupt Earth and its history, for their own advantage.
The other is the possibility that the time lords had in fact maneuvered the Doctor into these events precisely to uphold the “laws of time.” Meddling and at times conflicting gods abound in the Doctor Who universe.