Need for Following the Precedent of the Prophets (pbut)

Knowledge is obtained through the Guidance of Allah, for Allah alone is aware of realities. Allah offers this knowledge to man by means of Revelation. Revelation is transmitted to none but the Prophets (pbut). Allah has never published a Book and, having distributed to each individual, told him to study it to ascertain for himself the reality of his own existence and that of the universe. To realize his role in the practical world in the context of this reality, Allah has always appointed the Prophets (pbut) to convey this message to man, so that the Prophets (pbut) should not rest content with merely propagating their mandate, but driving it home, demonstrating it in action, recalling to the right path, those who defy the Divine mandates and organizing the believers into a society where every aspect bears practical evidence of this knowledge.
It is evident from this brief exposition that, for Guidance, we are wholly dependent upon the character displayed to the world by a Prophet of God (pbuh) A non-Prophet who does not believe in a Prophet is not eligible to be our leader, even though he may be a sage, a deeply learned and wise man. This is because such a person bereft of this knowledge is incapable of devising a true and just system of life for us.