Conclusion
I: The Doctor is a god, but he is a god who needs to not be a god. To behave as a god is to lose himself, to stop being the Doctor. Thats what happened to the Time Lords. They behaved as gods, behaved as if the universe were there for them to play with. The Master behaved as a god. What he did to earth was godlike: the psychic mesmerizing he created could be conceived as worship. And the Master was evil, and he died. The Doctor must never become like that. Sometimes, the Doctor needs his companions with him. They keep him close to Earth, remind him that to be a god is a terrible and lonely thing, remind him that his powers have and need limitations. Sometimes, the Doctor really ought not to have companions with him. Thats why the Ponds stopped being full time, why River and he never traveled together permanently: because for them to worship him was wrong, and did far more harm than good. When the Doctor acts too much like a god, when he starts to believe in his godliness, he needs someone who believes that he can be a man. Or else the universe will suffer. II:
Doctor Who asks a very simple and very complicated question: how could a god be good? How could there be a god who allowed terrible things to happen? What would the prerogatives of a god produce? The Doctor said once that good men don't need rules, and that's why he has to have so many. He is not a pure soul. And he knows it. Clara once asked what people could possibly be to the Doctor, from his godlike perspective. And his answer was that people were the only mystery worth solving. The only thing in the universe worth living for.
People are what can save us. Our potential, our ability to deal with the universe.
At our best, we can rise above the carelessness of the universe, can weather the battles of gods and devils.
Thats what the Doctors companions do. Thats what we all do, every day. We have the potential to be good. And when the Doctor follows our example, so does he.