Question: Why do the terrorists behead the hostages? Is that just for the effect it causes, the horror and fear it creates, or is there some other reason?
Answer: There is a precise reason: beheading is prescribed by the Qur’an for the purpose of forcing the entire world into submission to Allah. It is the penalty meted out to those who refuse to become Muslims: “Now when ye meet in battle those who disbelieve, then it is smiting of the necks…” (Surah 47:4). That is why beheading of non-Muslims was practiced by Muhammad and his early followers, and all through the history of Islam in its slaughter of millions, from France to China. The same is true today in Saudi Arabia, Indonesia, Sudan, Nigeria, Afghanistan, and anywhere else Muslims have the power to do so. Those who perpetrate this outrage against human rights and dignity are zealous Muslims who would deny that they are terrorists. They simply claim to be following Allah’s command and the example of Muhammad and his successors.
If the hostages who’ve been executed by terrorists in Iraq or elsewhere had been willing to become Muslims, they would have been spared. However, that option was probably not even offered, because it would undermine the threat of death used for bargaining purposes. The practice of beheading is a public notification that these are Muslims acting in obedience to Allah with the intention of terrifying the entire world into converting to Islam.