For court if you feel obligated to “defend your atheist character” as not being religious to many implies something somehow unethical, you could say, I am an atheist but my religion style, though I dont have one, would be closest considered or connected to humanism or secular humanism more specifically, alternatively you can say as for a type of religious persuasion, though I dont have one, would be closest considered or connected to how I am an ethical humanist, a universal ethicist or just ethicist. Sometimes we have to talk in a language they may understand.