Hang on. Do I have to believe in aliens and believe in what the First Book of the Grey says?

No and no. Not believing in aliens and not believing in what is written in the First Book of the Grey is about as close as you can get to being an orthodox member of the Church of the Grey, insofar as the concept of being orthodox can exist in a non-conformist disorganised and above all individually driven religion that actively encourages you to do your own thing from your own perspective.

Many members of the Church of the Grey do believe in Aliens. Many believe the aliens will or already have come. Some even think they are divine. A few even regard the first Book of the Grey as authoritative, to a degree at least. However, in the end, all that matters is: what do you believe?