It is understandable that you would not want to stalk the Earth in your true form as an otherworldly spiritual emanation of either good or evil. If you did that, with your tail, wings, many eyes, blinding halo or bale of hellfire, you would freak people out, and those who disagree with your raison d'etre would come after you with torches and pitchforks, like in the old movies.
What did you do? It's difficult to tell the specifics. Perhaps you took the visage of some poor mortal who took a bad step and fell in front of a train, or you invented a persona out of whole cloth, fabricating a life, relatives, friends, a job, et cetera, all in service of infiltrating humanity for whatever reasons you have.
We don't want to get in the way of your mission, good or evil. Frankly, with your divine or infernal powers, we are no match for you. We would, however, like to know whom you represent. Are you an angel? Are you a devil? Or are you something ... in between?
You may think us mere mortals no threat to your illusion, but we can pierce it. All we need is for you to answer a few short questions and we will know if you are secretly an angel or a devil!