And suppose God did reveal himself, but with the purpose of telling us that a bigger, badder, more powerful god took over his throne in Heaven and now God's just another impotent mortal. If he said then to Christians "But, you guys still love me, right?" What do you think the answer would be?
They claim he's Satan in disguise.
Better question: God reveals himself, and admits that the New Testament is a lie that he made up, and that Satan actually has taken over Heaven. He also reveals that the Old Testament is true. Also, Satan has a non-intervention policy, but is lax on it and breaks it to help the innocent and punish the guilty when he thinks they really need it. Purgatory also exists, but only because Satan created it, and Hell was infinite until Satan ended that, too, and made it temporary for most, barring completely horrible individuals like Ariel Castro, Hitler, Stalin, Richard Ramirez and the like. Also, Satan's Heaven operates on the "do good works, idgaf if you have faith, and most of the Bible rules are full of shit" rule. God acts exactly like the Old Testament God, and praises Israel for following the Old Testament quite well. How does the world react?