The second part of the Kalimah (Article Of Faith), on the other hand, signifies that God has not left man without any guidance for the conduct of his life. He has revealed His Guidance through His Prophets, and Muhammad (peace be upon him) was the last Prophet. And to believe in a Prophet means to believe in His Message, to accept the Law which he gave and follow the Code of Conduct which he taught. God manifest His love fir us by giving us guidance to truth through His revealations to His Prophets.
Thus the second basic postulate of Islam is to believe in the prophethood of Muhammad (peace be upon Him). to accept the religion which he presented and to follow his commands and his example.
Every Prophet of God, according to the Quran, strove to build man's reletionship with God on the principle of God's sovereignty and acknowledgement of the authority of the Prophet as a source of Divine Guidance. Every one of them said: "I am to you God's Apostle, worthy of all trust. So be committed to God, heed Him, and obey me."
The guidance is revealed through the Prophets. It is a part of their mission to translate it into practice, in their own lives and in the society they try to reform. All the Prophets are representatives of God, but they are human beings and their lives are models for mankind. Belief in the Prophets involves acceptance of the Shari'ah (the Path) and to implement it in all matters of daily life. This is how the Will of God is fulfilled on earth. The Quran says:
And about the last Prophet, it is explicitly stated that;
"Yet by your Lord, they will never believe until they name you judge concerning what they are disputing among themselves; then they will finf no inconvenience for themselves concerning whatever you have decided and will submit completely". (The Quran 4:65)