The first part of my remake of Zardoz by John Boorman.

Synopsis
In the year AD 2293, a post-apocalypse Earth is inhabited mostly by the "Brutals", who are ruled by the "Eternals" who use other "Brutals" called "Exterminators", "the Chosen" warrior class. The Exterminators worship the god Zardoz, a huge, flying, hollow stone head. Zardoz teaches:

The gun is good. The penis is evil. The penis shoots seeds, and makes new life to poison the Earth with a plague of men, as once it was, but the gun shoots death, and purifies the Earth of the filth of brutals. Go forth . . . and kill!

Special credit to endology for making the costume