Devout Muslims watching current Western debates, for instance, might notice that some of the same cosmopolitan liberals who think of themselves as Benevolent Foes of Islamophobia are also convinced that many conservative Christians are dangerous crypto-theocrats whose institutions and liberties must give way whenever they conflict with liberalism’s vision of enlightenment.

They also might notice that many of the same conservative Christians who fear that Islam is incompatible with democracy are wrestling with whether their own faith is compatible with the direction of modern liberalism, or whether Christianity needs to enter a kind of internal exile in the West.

And they might notice, finally, that all of the models for reconciling ancient faith to modern life tend to lurch between separatism and dissolution. The ghettoized “fortress Catholicism” of the 1940s gave way to the hemorrhaging “modernizing Catholicism” of the 1970s. The Americanized Judaism of midcentury is now polarized between a booming Orthodoxy and a waning liberal wing. The liberal Protestant churches have emptied, while Protestant fundamentalism remains a potent force.

In this landscape of options, the clearest model for Islam’s transition to modernity might lie in American evangelicalism — like Islam a missionary faith, like Islam decentralized and intensely scripture-oriented, and like Islam a tradition that often assumes an organic link between the theological and political.