I think the Bhagavad Gita is about both the forces of light and the forces of darkness that exist within our own self, within our own soul; that our deepest nature is one of ambiguity. We have evolutionary forces there - forces of creativity, and love, and compassion, and understanding. But we also have darkness inside us - the diabolical forces of separation, fear and delusion. And in most of our lives, there is a battle going on within ourselves.