The case of Abdul Rahman, the Afghani man threatened with execution for converting to Christianity, highlights one of the crucial distinctions between Islam and every other faith. Every faith has a triumphalist strain, a "we are right and all other must acknowledge it" doctrine. Thinking that we are right is necessary for any faith that believes in truth. But killing other people who disagree is beyond the line of civilization.
Sociologist John Murray Cuddihy, in The Ordeal of Civility and, especially, No Offense, catalogues the ways in which Judaism, Protestantism, and Roman Catholicism had to give up, or at least soft peddle, some doctrine that was too triumphalist for a mixed society. The Chosen People; the Great Commission to evangelize the Jews; No Salvation Outside the Church - each are still official teaching, but all have been put on the shelf so that we may live in peace with one another.
Islam teaches that everyone is really a Muslim, some just don't know it yet. Muslims are forbidden to convert to another faith. Muslim states are the hardest mission fields in the world because of this doctrine, harder even than the communist lands.
Every faith has had to give up on triumphalism in order to live in a civilized world. Islam will have to give this one up, sooner or later.
Sooner, at least in the state law of Afghanistan, would save Abdul Rahman from execution.