"He is God, there is no deity but He..." (Qur'an, 59:23);"Muhammad is the Messenger of God" (Qur'an, 48:29)

This is simply to testify in one's heart and speech that 'there is no deity but God and Muhammad is His Messenger'. A person is said to be Muslim, when he or she proclaims this statement in the audience of witnesses. The statement signifies a verbal commitment to Islam and an announcement to people that the person is Muslim. Apart from a ritual ablution performed by the individual in private, no public baptism or any other initiation is required. This was practiced every time a person wanted to convert to Islam at the time of the Prophet Muhammad. The same practice continues till today.

It is important to note that in Islam there is no forced or coercive conversion. The Qur'an itself says that there is no compulsion in religion (2:256). Instead, people are encouraged to investigate Islam and accept it of their own free will. At no time throughout the entire Muslim history did forced conversions take place. Those people who chose not to convert lived happily as 'protected citizens' under Muslim rule who were exempt from Muslim law and military drafting although they paid a special tax for the exemption.