I listen to quite a bit of Christian call-in radio (Steve Gregg's The Narrow Path), and one question that consistently drives me crazy is, "Do people from Religion X follow a different Jesus / worship a different God?"
The reason this bothers me is that, assuming as I do that God and Jesus exist, they are who they are. In other words, neither of them amounts to the sum of theological propositions you can levy in their favor. So if someone says he believes in God or Jesus, I take him at his word. However flawed his ideas of God or Jesus might be. And I think Paul gives me a good example in this regard:
Acts 17:22-25 (ESV, emphasis added):
22 So Paul, standing in the midst of the Areopagus, said: "Men of Athens, I perceive that in every way you are very religious. 23 For as I passed along and observed the objects of your worship, I found also an altar with this inscription, 'To the unknown god.' What therefore you worship as unknown, this I proclaim to you. 24 The God who made the world and everything in it, being Lord of heaven and earth, does not live in temples made by man, 25 nor is he served by human hands, as though he needed anything, since he himself gives to all mankind life and breath and everything.
Paul seems to be saying that the Greeks, with their pantheon of capricious gods, also worshipped the True God in ignorance. Now certainly he's not saying that worship of God as one of many gods is acceptable, but he is saying that God is who he is regardless of our conception of him.
Let me throw out a flawed analogy here. Johnny Goofoff and I had the same teacher in fourth grade: Mr. Hell (based on an actual and beloved teacher of mine). I was (with typical failings and episodes) a model student, and I found Mr. Hell to be funny and caring as well as firm and demanding. Johnny was a cutup and goof-off and found Mr. Hell to be a brutal taskmaster, always looking to find fault and punish him.
And yet when we talk of him, we're talking about the same man. Our perspectives on him are shaped by our experiences of him, but he's the same guy even if our descriptions and understandings of him are basically opposite.
Now, I don't believe this analogy fits, say, the differences between a Christian and a Muslim's perspective on God. But wait, there's more.
I have a son. Johnny has a son. We both tell our sons about Mr. Hell. They pass on the stories to their children. At no point is anyone telling their children about a man other than Mr. Hell. They may have very different ideas about him, to the point that someone might rightly say, "You're talking about a completely different guy," but there's still only the one man.
But what's really crucial is that none of the people now describing Mr. Hell ever actually knew him. They only knew about him. But the fact that they describe him differently doesn't change who he is. Neither does it change that they're describing the same person.
Does this make sense? I think it does. Then again, I often overestimate my ability to be clear.
Now, I must handle the one obvious objection, and here I'm stealing my friend Colin's thunder. What about the Aztecs? Were they worshipping God, cutting out people's hearts at their Temples? No, of course they weren't. Paul is pretty clear that the pagan gods are demons. Keep in mind that Ba'al and Chemosh and Molech and Dagon weren't considered "The One God" of their people. They were considered to be one god among many. In other words, I don't think it's a valid objection. The floor is yours, Mr. K.