What Is Kufr in Islam?

In Islam, the concept of kufr has been widely discussed among Islamic scholars for centuries. In Arabic, the term kufr literally means covering or concealing something, and in a religious context, it refers to hiding or denying religious truth. More specifically, the term indicates disbelief in Allah and His Messenger, Muhammad. Considered the opposite of iman, which means faith, kufr is considered a grave sin in Islam, punishable in the hereafter by hellfire.

The term kufr comes from the Arabic verb kafara, which means to cover up, conceal or deny. K-f-r, the three-letter root of both of these words, bears meanings that range from covering and hiding to disbelief, ingratitude, infidelity and godlessness. The active participle is kafir, a term signifying unbelievers, infidels, ingrates, atheists and the such.

In Islam, one who commits kufr, which means disbelief, is known as a kafir, or a disbeliever. Although the strict definition is argued among Islamic scholars, most Muslims agree that all non-Muslims are kafirs, or kuffar. The Ahl al-Kitab, a term which means "People of the Book," refers to non-Muslim followers of faiths that have a revealed scripture. According to the Qur'an, People of the Book include Jews, Christians, Sabians and Magians. And although they follow a revealed scripture, the Qur'an states that all non-believers of Islam will go to hell.

In order to be held accountable for kafir in the hereafter, it is believed that a level of accountability must have been established during one's lifetime. Although there are various viewpoints on the issue, it is generally agreed that children, the insane and all those who never once heard the shahadah, called the Declaration of Faith, uttered in a language familiar to them are generally not considered accountable and therefore are exempt from the punishments promised in the Qur'an to accountable kafirs.

In Islam, it is believed that kufr may arise in a variety of forms of which all faithful Muslims must be wary. Disbelief may arise from stubbornness to admit the truth, from pride and arrogance, from ingratitude towards Allah, from disobedience or unwillingness to comply with any one of the principles of Islam, from mockery of Allah's Prophets, signs or teachings or from the hypocrisy by those professing to believe while concealing unbelief.