Da‘wah [ˈdæʕwæ] literally means “issuing a summons” or “making an invitation”. Grammatically, the word represents a gerund of a verb with the triconsonantal root d-ʕ-w دعو meaning variously “to summon” or “to invite”. A Muslim who practices da‘wah, either as a religious worker or in a volunteer community effort, is called a dā‘ī (داعي, plural du‘āh دعاة [dʊˈʕæː]).
A dā‘ī, is a person who invites people to understand and accept Islam through dialogue and other techniques, may be regarded as a missionary inviting people to the faith, prayer and manner of Islamic life.
In Islamic theology, the purpose of da‘wah is to invite people, Muslims and non-Muslims, to understand the worship of God as expressed in the Qur’an and the sunnah of the prophet Muhammad (PBUH) and to inform them about Muhammad (PBUH).
Da’wah as the “Call towards God” is the means by which Muhammad (PBUH) began spreading the message of the Qur’an to mankind. After Muhammad (PBUH), his followers (RA) and the Ummah (Muslim community) assumed responsibility for it. They convey the message of the Qur’an by providing information on why and how the Qur’an preaches monotheism. Muhammad (PBUH) saw Islam as the true religion and mission of all earlier prophets (AS). He (PBUH) believed that their call had been limited to their own people but that his was universal. His mission as the final prophet was to repeat to the whole world this call and invitation (dawa) to Islam. Muhammad (PBUH) wrote to various non-Muslim rulers, inviting them to Islam.