Jihad

Jihad is from the Arabic jihād (Arabic: جهاد), from the root j-h-d meaning to strive, to exert effort, to struggle[1]. The literal sense is striving or struggle, with the connotation of disciplined exertion toward a worthy goal[2]. Classical Islamic vocabulary includes related forms: mujahid (one who struggles), ijtihad (interpretive effort in legal reasoning), and jihad fi sabil Allah (struggle in the path of God)[2].

the term has moral, spiritual, intellectual, and at times military senses, so sensational definitions are misleading.

Classical Islamic teaching distinguishes between greater and lesser jihad, based on a saying attributed (with debated authenticity) to the Prophet Muhammad[3]. The greater jihad (jihad al-akbar) is the inner struggle against ego, temptation, and moral failure[3]. The lesser jihad (jihad al-asghar) is outer struggle, including but not limited to armed struggle when conditions of just defense are met[3]. Most Muslim scholars throughout history have placed the inner moral struggle as the more fundamental of the two[2].

Classical Islamic law developed detailed rules for when armed jihad is permitted, what conduct is allowed during it (combatants only, no harm to civilians, no destruction of property of religious value, no harm to women, children, the elderly, or non-combatants), and what ends it must serve[4]. The classical conditions for legitimate armed jihad are restrictive; most Muslim scholars hold that contemporary terrorism violates these conditions decisively and is not legitimate jihad[2][4].

The everyday use of jihad in Muslim life often refers to ordinary moral effort: struggling to maintain prayer through a busy week, struggling to be patient with a difficult family member, struggling to keep a fast[5]. The Quran itself uses the term and related forms primarily in non-military senses[6].

Scholarly study of jihad spans Islamic law (fiqh), historical study of Muslim conquests and defensive wars, and contemporary analysis of extremism[3]. Important works by John Esposito, Michael Cook, and other scholars distinguish carefully between classical doctrine, historical practice, and modern political appropriation[3][7]. Comparative ethics places jihad alongside Christian just war theory and other religious traditions of ethical reflection on violence[3].

• No God but Godby Reza Aslan
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• What Everyone Needs to Know About Islamby John L. Esposito
  book