""There is no compulsion in religion" declares a famous verse (2:256).Higher criticism would be needed indeed.
How then came the ban on apostasy? Well, it was a political, not religious, verdict that soon became a part of the religious canon. David Forte, professor of Law at Cleveland State University, explains this fact very briefly and vividly in his article titled "Islam's Trajectory."
"The primary justification for the execution of the apostate is," he notes: "That in the early days of Islam, apostasy and treason were in fact synonymous. War was perennial in Arabia. It never stopped. To reject the leader of another tribe, to give up on a coalition, was in effect to go to war against him. There was no such thing as neutrality. There were truces, but there was never permanent neutrality. It is reported, for example, that immediately after the death of Mohammed, many tribes apostatized. They said in effect, "the leader whom we were following is gone, so let's go back to our own leaders.' And they rebelled against Muslim rule. The first caliph, Abu Bakr, ordered such rebels to be killed.
Many scholars argue that the tradition that all apostates had to be killed had its origin during these wars of rebellion and not during Mohammed's time. In fact, many argue that these traditions in which Mohammed affirmed the killing of apostates were apocryphal, made up later to justify what the empire had been doing."
The second thing that the origin of the apostasy ban shows is that Islamic sources need a serious reconsideration. What most Muslims attach themselves to as divine commandments are actually the political and cultural codes of the early centuries of Islam, which were, to be sure, man-made facts. The divine principles of a religion should remain eternally valid, but not its historical context."
Turkish Daily News, November 3, 2007