By Dan Merica, CNN

(CNN) - The possible hanging of Pastor Youcef Nadarkhani for converting from Islam to Christianity has exposed a division among Islamic jurists on whether Iran would be violating Islamic law by carrying out the execution.

According to some of these scholars, the Quran not only outlaws the death penalty for the charge of apostasy, but under Sharia law, conversion from Islam is not a punishable offense at all.

"Instead, it says on a number of occasions that God prefers and even demands that people believe in Him, but that He will handle rejection of such belief by punishing them in the afterworld," wrote Intisar Rabb, an assistant professor of law at Boston College and a faculty affiliate in research at Harvard Law School, in an e-mail to CNN.

But Rabb also acknowledges that there is a more nuanced view to Islamic law, too.

Clark Lombardi, an associate professor of law at the University of Washington, said there is more room for interpretation because the Quran is not the only source of Islamic law.

"Most Muslims look past the Quran and say the Quran needs to be looked at in the practice of the Prophet. So they look to see what rules the prophet laid down," Lombardi said.

And, according to Lombardi, if you look at literature about the life of Mohammed, "then apostasy is clearly something very bad. And there are examples of apostates being punished."

What emerges from this is a complicated division between whether apostasy is punishable in the first place and, if it is punishable, for what reason.

"Most Muslims, most but not all, believe that apostasy is a deep and terrible sin," Lombardi said. "The question of whether the state should punish deep and terrible sins is in fact something that Muslims do disagree about."

Nadarkhani, the leader of a network of Christian house churches in Iran, was first convicted of apostasy in November 2010, a charge he subsequently appealed. Though news reports from Iran have indicated the pastor is now charged with "security related crimes" and is no longer charged with apostasy, briefs obtained by CNN from the 2010 Supreme Court case show the pastor's original charge was solely apostasy.

"He (Nadarkhani) has stated that he is a Christian and no longer Muslim," states the Supreme Court brief. "During many sessions in court with the presence of his attorney and a judge, he has been sentenced to execution by hanging according to article 8 of Tahrir - olvasileh."

Harris Zafar, national spokesperson of the Ahmadiyya Muslim Community USA, does not mince words on the subject, stating in a Huffington Post opinion piece that "Islam prescribes absolutely no punishment for apostasy."

"Chapter two of the Holy Quran emphatically denies this possibility, stating 'there shall be no compulsion in religion," writes Zafar. "This is an unambiguous declaration protecting freedom of conscience and choice."

Mohammad Fadel, associate professor of law at University of Toronto, said that there is a difference, though, between just being a nonbeliever and being someone who is actively preaching a religion other than Islam. Fadel said Nadarkhani's preaching "may be viewed as a kind of treasonous comment."

"Even for people who reject Islam religiously, many still identify them with the religion culturally, even if they aren't religious," Fadel said.

According to Rabb, the idea for punishing apostasy stems from medieval times, when your religious affiliation was the basis for your citizenship. Renouncing your faith was also announcing your intent to no longer regard yourself a citizen of that community - in effect, treason.

But as time went on, your religious affiliation is no longer closely tied to your citizenship. "Now, we have an era of territory-based citizenship," Rabb wrote.

"The problem in the modern period is that contemporary states apply medieval rules in unreflective ways that do not often match the classical Islamic legal tradition to which they are trying to adhere," wrote Rabb.

But Lombardi points out that Iran is formally known as the Islamic Republic of Iran and "being Muslim is part of full citizenship in Iran." Though he couldn't speak for the Iranian justice system, he said there are two grounds for which Iran could give to put Nadarkhani to death for apostasy.

"One of them would be to say traditionally in Shiite Islam, people have interpreted the scripture for apostates to be put to death," Lombardi said. "The other one is that people who apostatize have committed a sin and they are real threat to the Muslim community and as a threat, they are punishable as someone who is a traitor to the country."

The website islawmix, a project through the Berkman Center for Internet and Society at Harvard University, was created to be an authoritarian voice on the nuances in Islamic law.

Made up of 13 scholars and founded by Rabb, along with Umbreen Bhatti and Kaizar Campwala, the website looks to connect "news readers, media producers, and legal scholars with credible, authoritative information about trends in Islamic law."

Bhatti, a practicing civil rights lawyer, said the nuances of Islamic law are not unique; the same sort of nuanced opinions are regularly found in American law.

"The reality is the 13 scholars on our sites could give you a variety of different responses," Bhatti said. Islamic law has a "rich legal tradition and it is important for us to not convey something definitive or to suggest there is one answer."

The overriding opinion of each scholar was simple - the complication of Islamic law makes it somewhat difficult to predict what Iran will do.

Lombardi recalled a story in Afghanistan, where a man's neighbors hauled him to court for leaving Islam.

"The judge takes a look and says this person is an apostate and therefore the crime should be putting them to death," Lombardi said. "But then the judge said, Islam is such great religion, you could have to be crazy to have to convert from Islam. And therefore, I think this person should get off on ground of insanity."

Moral of the story, according to Lombardi: "There are all sorts of grounds for pardoning someone."