What about Christianity, the third, and the largest, piece of the matrix? It seems to be, just like Islam, a universalization of Judaic monotheism. But Christianity introduced a new theological element to the scene — a divine Christ and triune Godhead — which proved unacceptable to both Judaism and Islam. In the chapter comparing the Quran with the New Testament, Miles shows this by explaining how Islam rejects Christian theology, while showing great respect for Jesus Christ and Mary. He also sees “a brilliant symmetry” in how Islam combined Judaism’s criticism of Christian theology with Christianity’s criticism of Jewish particularism.

The book underlines other distinctions between Yahweh and Allah. The former comes across as more disputable and “less absolute and overwhelming.” Allah, on the other hand, appears as more “compassionate.” And while Allah offers both great promises and threats for the afterlife, Yahweh is focused on this world.

In observing such nuances, Miles, a Christian, is as objective, fair and gracious as one can get. In the beginning, he declares his own “suspension of disbelief,” which means letting go of his non-Muslimness and reading the Quran on its own terms. At the end, he turns back to his faith and reminds us: “The Bible is my Scripture, the Quran is theirs.” Yet by reading the latter with respect, he thinks non-Muslims can find it “a little easier to trust the Muslim next door, thinking of him as someone whose religion, after all, may not be so wildly unreasonable.”

Non-Muslims who take the time to read the Quran may end up feeling a bit baffled, though. For they will hear a lot about Abraham, Moses, Joseph or Jesus, but almost nothing about the person they may be expecting the most: Muhammad. For while the Quran often speaks to Muhammad, it almost never speaks about him.

That is why the Islamic tradition developed a post-Quranic literature on the life and times of Muhammad, recorded in the books of sira, or biography. And a cutting-edge version of sira comes from the pen of Juan Cole, a professor of history at the University of Michigan and the author of the popular blog Informed Comment.

Cole’s book, “Muhammad: Prophet of Peace Amid the Clash of Empires,” is not just eruditely informative, but also ambitiously revisionist, with two unorthodox arguments he keenly advances throughout the book.

The first argument links the birth of Islam in early-seventh-century Arabia to the major geopolitical conflict of the time — the clash between the Christian Byzantine Empire based in Constantinople and the Zoroastrian Sasanian Empire based in today’s Iran. Cole’s starting point is the Quranic sura, or chapter, titled “Romans.” “The Byzantines have been defeated in a nearby land,” it reports, but also heralds that their victory will come soon, adding that “on that day, the believers will rejoice.” This famous passage has traditionally been taken as an indication of sympathy among early Muslims for Christians as fellow monotheists against pagan enemies. But Cole thinks there is much more to it, postulating an alliance with Rome in which Muslims became “members of the eastern Roman Commonwealth.” It is an interesting theory to consider.