I don't see that this could be serious. Then again, it seems misinformed enough.
But I find it strange that everyone says that the Muslim God is the Christian God is the Jewish God. Sure, their history makes them linked, but they aren't quite the same.
There are important differences between the conceptions of their Gods that make them quite distinguishable.
The Islamic God doesn't go in for silly things like original sin, or the Trinity.
The Christian God might be a hippy, depending on who you ask. Also, Trinity.
The Jewish God likes to kill stuff that pisses it off. Just for shits and giggles.
The Jews don't usually think that the Christian God (Trinty etc) is their God too. Though the Christians think so, but the Jews see/saw them as crazy heretics. But Christians don't see the Muslim interpretation of God as legitimate either, despite the Muslim claim that they are technically the same God and the Christians just messed up.
Point being, that this person is not insulting his God. Because Ming here simply doesn't accept Muslim claims. Okay, so he also is being an asshole about it.