Allah T'ala sent the Prophet Muhammad (s.a.a.w.) as شَاهِدً
Allah T'ala says in the Holy Quran:
يَا أَيُّهَا النَّبِيُّ إِنَّا أَرْسَلْنَاكَ شَاهِدًا وَمُبَشِّرًا وَنَذِيرًا
O Prophet, We have sent you as a witness, a bearer of good news and a warner. (33:45)
The meaning of the Prophet's being a "witness" is very vast. It includes three kinds of evidence:
(1) Verbal evidence, i.e. the Prophet should bear out the truth of the realities and principles on which Allah's Religion is based and tell the world plainly that they are the truth and all that is opposed to them is falsehood. He should rise to proclaim without hesitation and fear the Being of Allah and His Unity, the existence of the angels, the corning down of Revelation, the occurrence of life-after-death, the Hell and Heaven, all are realities, even if they appear strange to the world, and the people mock the one presenting them, or call him a madman.
Likewise, the Prophet should openly present before the people the concepts, values, principles and rules pertaining to morality and civilization and social life that God has revealed to him, and reject as wrong all the concepts and ways which are prevalent and are opposed to them, even if the whole world rejects them as wrong and violates them in practice. Similarly, the Prophet should proclaim as lawful what is lawful in Allah's Law even if the whole world regards it as unlawful, and should proclaim as unlawful whatever is unlawful in Allah's Law even if the world regards it as lawful and pure.
(2) Practical evidence: That is, the Prophet in his own life should practically demonstrate all that he has been commissioned to present before the world. His life should be free from every shade of that which he calls evil, and his own character should clearly reflect that which he calls good; he should be the foremost in carrying out what he regards as obligatory, and most cautious in refraining from what he calls sinful.
