A third thing that surprises me when people start talking about who's saved and who's not:
Some people (though practically they have religion-specific loyalties) will shy away from any statement of definite, circle-boundary markers.
(1) For instance, some people immediately try to emphasize a case that seems like an intuitively plausible counter-example. Upon hearing that a person must be baptized, such a person will rebut, "but what if a person believes x, y, and z about Jesus and has repented and is on their way to the baptistry and dies? Will God really condemn that person?"
But the trouble here is that "(1)" is a slippery slope. If i 'expand the circle' one step for every one of these kinds of cases, then eventually there are no boundaries whatsoever. If i said, "okay, well a person must repent," the counter example could be the sincere person who has assented to x, y, and z about Jesus but dies just before the point of repentance. Then the next counterexample could be the person who dies just before they otherwise would've believed x, y, and z about Jesus. Then the person who would've listened to the gospel had they heard it, etc. etc. If these kinds of counterexamples are allowed to refute one demarkation between who's saved and who's not, then they refute all of them and there's no difference between who's saved and who's not.
(2) Or someone will argue that you can't be confident in any definite boundary marker, because if you had been born and raised under different circumstances, you wouldn't have come to believe in that definite boundary marker. So you can't say that Catholics are 'out' because if you had been born in Mexico, you'd likely have been Catholic and wouldn't believe that Catholics are 'out.' Or you can't say that Buddhists are lost because had you been born in Tibet, you'd likely have been a Buddhist and wouldn't believe that Buddhists are lost. Thus anything you believe which draws a definite line between who's saved and lost is really just a product of your upbringing. So you can't really say who's saved and who's lost.
The trouble with "(2)" though is that it's self-defeating. If "(2)" is true, then had the person who believes and argues for "(2)" been born under different circumstances, she likely wouldn't believe that "(2)" was true. If "(2)" is true, then belief in "(2)" is not rational or justified, but merely a product of one's upbringing, the same as the exclusivist claims that "(2)" is meant to defeat.
Thus, anyone arguing against exclusive claims by way of something like "(1)" or "(2)" either holds a position that is self-defeating or collapses into relativism.