Darren Oldridge argues that it's a mistake to think Islamist terrorism isn't an authentic expression of religious belief. For it expresses, he says, the sincere faith that there is only one road to salvation - a claim not unique to Islam but one that was also made historically by Christianity. The claim to the universal truth of what faith reveals is the source of the problem:
The New Testament is emphatic about the unique role of Christ in the scheme of salvation; the Koran is equally clear that this claim is untrue. The acknowledgement that both Christianity and Islam offer a route to salvation requires that each of these claims be qualified.Extrapolating from this... A framework for public life based on accepting that there is no single 'road to salvation', or - put otherwise - no single overriding moral truth, or that there is no way to be completely certain about whatever moral truth there may be, would seem to be the only alternative to permanent warfare between people of different belief systems (and that applies, of course, not only to religious belief systems). Call this framework 'pluralist liberalism'. Is it not itself premissed, then, upon principles for which universal validity is claimed by its adherents? Some would say no, but I've never seen a persuasive argument for that. Liberalism makes a claim of its own to moral truth, but it's a moral truth permitting those who believe in competing moral truths to live together, provided they don't try to impose these on one another by violence. Which means that liberalism has to exclude the attempts of antithetical belief systems to monopolize the public domain for themselves. If there is an air of paradox about this, I don't know how to resolve it.