I recently came across an interesting argument against religious pluralism, the view that all roads lead to God. I recommend reading the article here before reading my thoughts on the matter.
The argument is basically that if all religions are bona fide paths to God, and there is thus no reason to persuade others that one religion is better than any other, then God was cruel to crucify Jesus for the sins of mankind. If Christ isn’t the only way to achieve salvation and access God, then the crucifixion was simply gratuitous. Why allow your son to suffer beyond measure when it achieves nothing? This makes God out to be anything but the epitome of love and compassion; rather, He would be the epitome of a cruel potentate who frivolously allows people to suffer, even His own Son. This seems to me a good argument.
There’s one caveat I’d like to mention, however: this argument only works if the particular brand of pluralism against which we are arguing holds that all religions are true. A pluralist may not affirm this; he may affirm, for example, that all religions are mostly false in their claims, but they will get you to God because He respects the effort, even if it was misplaced, or some such other thing like this. If this be the case, then the pluralist may deny that the crucifixion is true, and the argument becomes a non sequitur. The argument needs an affirmation of truth with the respect to the resurrection. If this is secured, mount this argument; if not, look elsewhere. That’s my take on it.