The Islamic principle of divine guidance appears in detail in Tabataba'i 123ff. Ali (1988:84a) defines it briefly.
"The khilafat-e-Ilahia was the apostleship and after the conclusion of the apostleship with the Holy Prophet Muhammad, it was conveyed to Imamate, the divinely inspired heavenly guidance through the godly ones purified by God Himself, who were born pure, who lived pure and who surrendered themselves in the way of the Lord in all purity, which historic fact is unanimously acknowledged by the Muslim world as a whole.
Islam demands faith in these Holy Imams as in the apostleship of God, as the all-Truthful, holy and infallible guides divinely commissioned for the preservation of verbal form and the true meanings, both external and internal, of the Holy Qur'an, the final Word of God, as its authentic custodians and the divinely inspired interpreters and the correct models of godly life on earth to be copied by their devotees. The series of Imamate starts with All ibne Abi Taleb and ends with Muhammad ibnul Hasan Al-Mahdi, the last and living Imam of the Age."
The salient features of the Imamate as conceived in Islam are therefore that it is a necessary continuation of revelation implied in the institution of prophets. Its representatives are divinely appointed through revelation to their successors. The Imams are pure and infallible. They are custodians and interpreters of the prophetic revelation. They are models of godly life to be copied. They appear in a series of twelve, and there is always a living one, even if he is in a state of occultation.
Prophets can tell us what to do, but may not be able to make us understand in practice how to do it. They can call us away from sin and rebellion against God, but they cannot keep us from falling into formalism and hypocrisy. Humanity needs something more than the revelation brought to the prophets at the hand of angels and inscribed in holy books. We need implementation. In order to do something properly, you need first verbal instructions (the prophets) and then a live demonstration (divine guidance). What God reveals in words by the prophets He reveals in action, in flesh and blood, by the divine guides.
Without divine guidance we cannot apply the true import of the prophetic revelation. `Philip ran thither to him, and heard him read the prophet Elias, and said, Understandest thou what thou readest? And he said, How can I, except some man should guide me?' Acts 8:30-31. This statement by the Ethiopian shows clearly that the writings of the prophets are not enough. There must also be a divine guide to implement them in practice.
Throughout the Bible there are figures who are revelations of the will of God in action. Some of these are also prophets, such as Abraham. Abraham was a prophet (Genesis 20:7), but he was also a demonstration in action, a divine guide. This is shown by his action in giving his son over to be sacrificed.
A prophet brings the verbal principle, but a divine guide applies the theory to practice. Divine guidance sometimes seems to be contrary to the law, especially when the law is interpreted hypocritically or legalistically. Christianity has generally made this mistake. For example, because Jesus rejected the washing of hands before eating, Christians have assumed that he rejected all ablution with the exception of baptism. Mere scholarship and study cannot settle this issue. It would have to be settled by an authoritative figure.
A good example of the principle of divine guidance is in Jesus' judgement of the adulteress in John 8:1-11. According to the literal interpretation of the law, she should have been stoned to death. But the divine guide knew the situation. He was able to apply the law both justly and mercifully. He said, `He that is without sin among you, let him first cast a stone at her.' He neither abandoned the law, nor made an unjust verdict.
The knowledge of the divine guide or divine proof comes directly from God. Such a person is able to penetrate the heart of the circumstances and make a just verdict without being taught or informed in human institutions. Jesus is the supreme example of divine proof in the Bible. `But Jesus did not commit himself unto them, because he knew all men, and needed not that any should testify of man: for he knew what was in man.' John 2:24-25. His direct revelation was a source of marvel to the rabbis, who depended on long years of study to acquire the ability to make verdicts. John 7:15: `And the Jews marveled, saying, How knoweth this man letters, having never learned?'
According to Islam, God requires adherence to the living witness of his will just as much as to the verbal witness of the prophets. It was not enough for salvation to follow the faith of Adam and Seth: it was essential to follow Noah into the ark. Those who performed their prayers faithfully and claimed to be believers and followers of the one true God, but who failed to enter the ark, drowned. It was not enough to keep the ten commandments in Egypt: it was necessary to follow Moses through the waters of the Red Sea. It was not enough to claim to be the children of Abraham in the first century Ate. It was essential, according to Christian Scripture, to accept and follow Jesus Christ.
There is a strange aspect of the experience of divine guides in the Bible that sets them apart. That is the experience of occultation, that is, being secretly taken away from the visible world. There are three examples of this in the Bible:
Genesis 5:24. `And Enoch walked with God: and he was not; for God took him.'
2 Kings 2:11. `And it came to pass, as they still went on, and talked, that, behold, there appeared a chariot of fire, and horses of fire, and parted them both asunder; and Elijah went up by a whirlwind into heaven.'
Acts 1:9-11. `And when he had spoken these things, while they beheld, he was taken up; and a cloud received him out of their sight. And while they looked steadfastly toward heaven as he went up, behold, two men stood by them in white apparel; which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, who is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.'
Precisely the same kind of occultation is claimed in Islam for the Imam of the Age. Tabataba'i on page 154 says, `After the martyrdom of his father, al-'Imam al Mahdi (AS) had al-Ghaybat al-Sughra (the Short Occultation of al Imam Muhammad al-Mahdi [AS]) by the order of Allah and answered the questions of the Shi’as and resolved their problems through Al-Nuwwab al-Arba'ah (the Four Deputies of Imam al-'Asr (AS) who had successively attained the eminent position of being the Imam's (AS) Deputy. The Imam (AS) then had al-Ghaybat al-Kubra (the Great Occultation of al-'Imam Muhammad al-Mahdi [AS]) until the time when he will appear by the order of Allah to administer justice in the whole world after it gets overwhelmed with injustice and oppression.'
What is above all most important about the divine proof is his authority. Just as it is fatal to reject a true prophet, it is perhaps doubly fatal to reject the divine guide. To reject the divine guide and yet cling to the prophet is to fall into legalism, hypocrisy and formalism.
Jesus said, `All power (Greek: authority) is given unto me in heaven and in earth.' Matthew 28:18. Some of the people in Jesus' time did not understand the necessity of following the divinely appointed authority. It was enough for them to have Abraham as their father.
In Matthew 19:16-23 there is the story of a young man who asked Jesus what he should do to have eternal life. Jesus gave him the first step, the answer of the prophets, to keep the commandments. The young man had kept the commandments all his life, but still realized that he lacked something. He asked Jesus what he lacked. Then Jesus revealed the principle of divine guidance in its glorious clarity: Matthew 19:21. `If thou wilt be perfect, go and sell that thou hast, and give to the poor, and thou shalt have treasure in heaven: and come and follow me.'
The answer is full surrender to the one divinely appointed and sent from God. The criterion is not how well the commandments have been kept. Perfect keeping of the commandments is perhaps worse than none at all, when it allows the individual to think that he has bought God off by well doing. The young man's keeping of the commandments merely contributed to his being lost. It is possible to keep the commandments literally, but we must go beyond keeping the commandments to love God with all the heart and soul and mind. We attain that necessary love in surrendering and submitting to the one sent from God.
As the Bible presents divine guidance, it is all a matter of relationship. The legalist thinks that it is enough to do the right thing. But if you do the right thing and at the same time ignore and reject the one in flesh and blood who perfectly represents right, it shows that there is no true love of right. Love of ideals and principles is a hateful thing if it is combined with hatred of those people who most perfectly live by those ideals and principles. At the time of Noah, all those who thought it was enough to keep the commandments perfectly were lost. All those who attached themselves to Noah, no matter how imperfectly they carried out the commandments, were saved from the Flood. It is a matter of attachment.
According to the Bible, God has made it so that we are required to find out who the living divine proof is, and to attach ourselves to him in love, loyalty and obedience. This is why God speaks of those who `love me, and keep my commandments'. It is the attachment of love which comes first and is decisive. The New Testament gives such a role to Jesus. Such loving attachment naturally produces obedience. `The love of Christ constraineth us.' 2 Corinthians 5:14.
It is clear at this point that throughout the Bible there appear figures who bring the revelation of God's will into action and practice. In every time period, according to the Bible, those who accepted and followed these divine proofs sent from God were successful in pleasing God and obeying Him. The Bible comes to a climax in a great divine guide, the promised Messiah, Jesus Christ. It is the principle of the Imamate, or divine guidance, that makes the entire New Testament relevant. Without such an authority figure, the Hebrew Scriptures, coupled with Rabbinical method, clearly suffice.