The The word ‘Caliph’ is the English form of the Arabic word ‘Khalifa,’ which is short for Khalifatu Rasulil-lah. The latter expression means Successor to the Messenger of God, the Holy Prophet Muhammad (peace be on him). The title ‘Khalifatu Rasulil-lah’. was first used for Abu Bakr, who was elected head of the Muslim community after the death of the Prophet.
The Significance of the Caliphate
The mission of Prophet Muhammad (peace be on him), like that of the earlier messengers of God, was to call people to the worship of and submission to the One True God. In practice, submission to God means to obey His injunctions as given in the Holy Qur’an and as exemplified by Sunnah (the practice of the Prophet). As successor to the Prophet, the Caliph was the head of the Muslim community and his primary responsibility was to continue in the path of the Prophet. Since religion was perfected and the door of Divine revelation was closed at the death of the Prophet, the Caliph was to make all laws in accordance with the Qur’an and the Sunnah. He was a ruler over Muslims but not their sovereign since sovereignty belongs to God alone. He was to be obeyed as long as he obeyed God. He was responsible for creating and maintaining conditions under which it would be easy for Muslims to live according to Islamic principles, and to see that justice was done to all. Abu Bakr, at the time he accepted the caliphate, stated his position thus:
“The weak among you shall be strong with me until their rights have been vindicated; and the strong among you shall he weak with me until, if the Lord wills, I have taken what is due from them… Obey me as long as I obey God and His Messenger. When I disobey Him and His Prophet, then obey me not.”
The Rightly-Guided Caliphs (Al-Khulafa-ur-Rashidun)
Those Caliphs who truly followed in the Prophet’s foot steps are called ‘The Rightly-Guided Caliphs’ (Al-Khulafa-ur Rashidun in Arabic). They are the first four Caliphs: Abu Bakr, ‘Umar, Uthman and Ali. All four were among thc earliest and closest Companions of the Prophet (peace be on him). They lived simple and righteous lives and strove hard for the religion of God. Their justice was impartial, their treatment of others was kind and merciful, and they were one with the people – the first among equals. After these four, the later Caliphs assumed the manners of kings and emperors and the true spirit of equality of ruler and ruled diminished to a considerable extent in the political life of Muslims.
It should be clearly understood that the mission of Prophet Muhammad (peace be on him), and hence that of the Rightly-Guided Caliphs, was not political, social or economic reform, although such reforms were a logical consequence of the success of this mission, nor the unity of a nation and the establishment of an empire, although the nation did unite and vast areas came under one administration, nor the spread of a civilization or culture, although many civilizations and cultures developed, but only to deliver the message of God to all the peoples of the world and to invite them to submit to Him, while being the foremost among those who submitted.
What About the Present?
The primary responsibility of an Islamic government is still the same as it was in the days of the early Caliphs: to make all laws in accordance with the Qur’an and the Sunnah, to make positive efforts to create and maintain conditions under which it will be possible and easy for Muslims to live an Islamic life, to secure impartial and speedy justice for all, and to strive hard in the path of God. Any government which is committed to such a policy is truly following the message delivered by the Prophet (peace be on him).
Source : http://famousmuslims.blogspot.com