Of course it hasn’t. Every religious teaching is a doorway to god. The point of a door is to walk through it, not worship it. Once you walk through the door, it’s behind you, and how you passed from there to here doesn’t matter. The Course, like the Bible or the Buddha or mushrooms or long walks in nature, can act as a touchstone to help realign you when you feel out of step with yourself. Like any of these, it’ll become toxic if you put yourself in wrong relationship to it — fixated on the thing itself rather than the experience it can help bring you to.