Despite the way the question is phrased, it's not really "can God deceive about his nature", the question is "can some other being, who resembles God but has a different nature, deceive you into thinking he has the first type of nature". It doesn't sound like those religious answers you describe are addressing that question.
Does anyone know of an apparently defensible response to the following question?
How does a theist distinguish by any imaginable experience between an omnipotent and loving Being, and an omnipotent Being that just wants you to believe it is loving?
Or, if you prefer:
Out of all potential omnipotent beings that want you to believe that they are loving, what observation can distinguish those which actually are loving?
Also, are any of you aware of another who has posed this question?
EDIT: I'm confused at the apparent disapproval of many. Is it because the question refers to religion?