A religious or Holy War is one caused by, or justified by, religious differences. Most religions have a tradition of people fighting and dying for the faith as religious martyrs in the belief that this is what God wants his followers to do. A Holy War has religion as its driving force.

There are three elements:

  1. The achievement of a religious goal.
  2. Authorized by a religious leader.
  3. A spiritual reward for those who take part.

It is generally felt that there are five causes of Holy War:

  1. To spread the faith.
  2. To restore the faith in countries that once belonged to it.
  3. To rescue believers from unbelieving countries.
  4. To recover and purify sacred places that had been captured by non-believers.
  5. To get revenge against those who had committed blasphemies against the faith or believers.

The legitimate authority for declaring a Holy War is not the government, but the Church or the religious leadership of the faith.