By definition, a Muslim is someone who voluntarily submits to the will of God and regards making peace as their task. One becomes a Muslim by declaring that there is no god but the One and that Muhammad is the Messenger of God. In the broadest sense, a Muslim is someone who voluntarily and consciously surrenders to God's will. Therefore, all prophets who preceded Prophet Muhammad were also Muslims. The Quran mentions Abraham in particular, who lived long before Moses and Jesus and was "neither Jew nor Christian" but "Muslim" (Quran 3:67), because he had submitted to God's will.

On the other hand, there are people who call themselves Muslims but do not subordinate themselves to God's will, while others do their best to lead an Islamic way of life. One cannot judge Islam by only looking at people who bear a Muslim name but do not behave like Muslims in their actions and lifestyle. To what extent someone is a Muslim depends on the readiness with which they surrender to the will of God in faith and deed.