Our belief regarding Caliphate is that it is a God-given authority, like prophethood; although only a prophet can receive divine revelation of prophethood; and the functions of the Caliph are as follows: propagation and explanation, providing details of the brief and exegesis of difficult issues; application of words to the implications and details; and to fight on the interpretation of Quran1 in the same way as the Prophet fought on the basis of revelation of Quran
It is an expression of what the Prophet was unable to introduce or the time for which had not been ripe to act on it, or the people did not have the capacity to bear it, or other causes; thus all those, who are appointed as prophets or caliphs from Almighty Allah, it is a divine grace for them and it is their function to make people proximate to obedience and remove them from disobedience as it is obligatory on Allah to make this appointment.
That is why He created them and called them to His worship and obedience and He taught them what they did not know and did not leave the human beings free like cattle so that they may eat and enjoy and remain engrossed in pleasures.
On the contrary, He created them so that they may recognize Him and He gave them capacity to achieve His pleasure. He also made this easy for them through sending of prophets and revealing scriptures in every period of time.
Since every prophet does not have a lifespan as long as the tenure of the world and they are not supposed to live forever, and the religious codes of laws (Shariat) have capacities to last longer; thus, whenever a prophet passed away, his Shariat remained valid for a time; after which it was necessary to repeal it through introduction of a new Shariat. As there would be laws, which have not been announced even though they were framed; or there are some laws the time to act upon which has not arrived; and new laws.
In such circumstances, it is not logical that the Ummah should be left without a guardian, because all the people are included in divine grace, which is obligatory on God and is same for all. Hence, it is obligatory for Him to appoint someone to safeguard the religion; that he may take religion to perfection, remove doubts of disbelievers through evidence and remove darkness of ignorance and prevent attacks of the enemy and with his hand and tongue, he should cure deviations and weakness.
When Almighty Allah has concern for the creatures and regards it obligatory to do good to them, He has to select leaders for them to bear this important function and perform all these duties. He should act like a prophet, whose successor he is and in whose words, his successorship was announced. Therefore, the Almighty Allah cannot leave the people to their devices, without appointing a successor of the prophet, leaving the people in lurch.
Did Abdullah bin Umar not say to his father (Umar):
“People ask that will you not appoint anyone as Caliph after you? Now, if you had some quadrupeds or cattle, would you have left them to their devices? If you did that it would be said that you were neglectful. Whereas the matter of leadership of people is more important than cattle and camels. What justification would you offer to the Almighty Allah if you meet Him, without having appointed anyone as Caliph?”2
Ayesha said to Ibne Umar: “O son of my near kindred, convey my greetings and tell him not to leave the Ummah of Muhammad without a guardian. Appoint a Caliph for them and not to desert them after him, as I fear mischief for them.”3
And this is Muawiyah bin Abu Sufyan, who in appointing Yazid as Caliph, relied on this logical command completely and said: “I fear leaving the Ummah of Muhammad after me like a herd of cattle, without a shepherd.”4
Alas, if I only knew how the Prophet became neglectful of appointing a Caliph?! And how they blame the Prophet for this mistake?!
Entrusting this matter (appointment of Caliph) to members of public or to influential persons is not allowed, because common sense regards some conditions to be necessary in the Imam and some of them are personal and concealed and only the Knower of unseen is aware of them: like infallibility, divinity of soul and purity of self, so that he may ward off selfish desires; and knowledge; that he may not be misguided in any command, and other qualities, which are presented to the self and soul, and only its external parts become apparent
وَرَبُّكَ يَعْلَمُ مَا تُكِنُّ صُدُورُهُمْ وَمَا يُعْلِنُونَ
“And your Lord knows what their breasts conceal and what they manifest.”5
اللَّهُ أَعْلَمُ حَيْثُ يَجْعَلُ رِسَالَتَهُ
“Allah best knows where He places His message.”6
Thus, the Ummah, which has no unseen knowledge, cannot distinguish who is imbued with these qualities. People cannot differentiate good from evil. When a prophet like Moosa chose seventy persons from thousands of his followers and before them asked Almighty Allah to manifest Himself, how ordinary people can select a person like that and how they could assure that they would not select a transgressor, or a deviated person?