The duty of enjoining the good and forbidding the evil (al- 'amr bi al-ma'ruf wa al-nahy 'an al-munkar)means summoning people to Islam, as well as resistance against injustice, opposing and struggling against oppressors, and endeavoring to ensure that public wealth and income derived from war are distributed in accordance with the just laws of Islam, and that taxes are collected, levied and expended in due and proper form.