Both monotheism and polytheism have degrees and stages. Unless a man passes through all the stages of monotheism, he cannot be a true monotheist.
To acknowledge the unity of His essence means that Allah is One in His essence. The first impression of Allah which anybody has is that of His Self-dependence. He is a Being who is not dependent on any other being in any way. In the words of the Holy Qur'an, He is Ghani (the Absolute). Everything depends on Him and seeks His help. He is independent of everything. The Holy Qur'an says:
"O men, it is you who stand in need of Allah. As for Allah, He is above all need, worthy of praise." (Surah al-Fatir, 35:15)
The philosophers describe Him as Self-existent or as a being whose existence is necessary.
The second impression of Allah which everybody has is that of His creatorship. He is the Creator and the ultimate source of all the existing things. All things are "from Him". He is not from anything. According to the philosophical terminology, He is the First cause.
This is the first conception of Allah which everybody has. Everybody thinks of Allah, and while thinking of Him, he has this conception in his mind. Then he decides whether there, really exists a truth, which is not dependent on any other truth, and from which originate all other truths.
Unity of essence means that this truth is not multiplicable, and has no like of it. The Holy Qur'an says:
"Nothing is similar to Him." (Surah ash-Shura, 42:11)
"And there is none comparable to Him." (Surah at-Tawhid, 112:4)
The rule that an existing being is always a member of a species, is applicable to the created beings only. For example, if is a member of the human species, we can presume that may be other members of this species. But no such thing be presumed in the case of the Self-existing Being. He is above all such notions.
The Self-existing truth being one, this world has only one source and one end. It has neither originated from various sources nor will it return to various sources. It has originated from one source and one truth. The Holy Qur'an says:
" Say: Allah is the Creator of everything." (Surah ar-Ra'd, 13:16)
Everything will return to the same source and the same truth:
"Do not all things reach Allah at last?" (Surah ash-Shura, 42:53)
In other words, the whole universe has one centre, one pole and one orbit.
The relation between Allah and the world is that of the Creator and the created, that is the relation of the cause and the effect, not that kind of relation which exists between light and lamp or between human consciousness and man. It is true that Allah is not separate from the world. He is with everything. The Holy Qur'an says: "He is with you wherever you are." (Surah al-Hadid, 57:4)
Anyhow, the non-separation of Allah from the world does not mean that He is to the world as light is to a lamp or as consciousness is to a body. Had it been so, Allah would have been the effect of the world, not the cause of it, as light is the effect of a lamp. Similarly the non-separation of Allah from the world does not mean that Allah, the world and man, have the same orientation and they all move and live with the same will and spirit. All these are the attributes of the created and non-self-existing beings. Allah is free from them. The Holy Qur'an says:
"Glorified be your Lord, the Lord of Majesty, from that which they ascribe to Him." (Surah as-Saffat, 37:180)
The unity of His attributes means to recognize that the essence and the attributes of Allah are identical and that His various attributes are not separate from each other. The unity of essence means the negation of there being any peer or like of Allah and the unity of His attributes means the negation of any kind of multiplicity or plurality within His essence. Allah has all the attributes implying the perfection of majesty and beauty, but His attributes have no aspect really separate from Him.
The separation of the essence from the attributes and the separation of the attributes from each other, are the characteristics of the limitation of existence, and are not conceivable in the case of infinite existence. Multiplicity, combination and the separation of the essence and the attributes are inconceivable in the case of the Absolute Being. Like the unity of the Divine essence, the unity of the Divine attributes is an Islamic doctrine and one of the most valuable human ideas which has exclusively crystallized in the Shi'ah school. We here quote a passage from the first sermon of the Nahjul Balaghah 1 which corroborates as well as explains this idea:
"All praise is due to Allah, who cannot be adequately praised by any rhetoricians, whose blessings cannot be counted by any enumerators, whom due homage cannot be paid by the most assiduous, who cannot be fully comprehended howsoever one may try, who cannot be reached by intelligence howsoever deep it may go, whose attributes are not limited by any limitation. There exist no words to describe Him fully."
As we see, in the above passage the boundlessness of the Divine attributes has been emphasized. In the same sermon after a few sentences Imam Ali says:
"Perfect devotion to Him means to deny the imputation of attributes to Him, for the person to whom an attribute is imputed, bears witness that he is different from the attribute imputed to him and every attribute of him bears witness that it is different from the person to whom it has been imputed. He who imputes an attribute to Allah compares Him (to something and he who compares him. . .". (See: Sermon - 1, p. 137, Peak of Eloquence, ISP, 1984)
In the first passage it has been affirmed that Allah has attributes (whose attributes are not limited by any limitation). In the second passage also it is confirmed that He has attributes, but instruction has been given to impute no attributes to Him. The wording of these passages shows that the attributes which He has are unlimited like the limitlessness of His own self, that they are identical with His essence, and the attributes from which He is free are those which are limited and separate from His essence and from each other. Thus the unity of the Divine tributes means to acknowledge the unity of Allah's essence and His attributes.
Unity of His work means to recognize that the world with all its systems, ways, causes and effects is the work of Allah alone and has originated from His will. Nothing in the world is self-existing. Everything depends on Him. In the words of the Holy Qur'an, He is the sustainer of the whole world. The existing things are not independent with regard to their effect and causation. As a result, as Allah has no partner in his essence, similarly He has no partner in His work. Every agent and every cause owes its existence and effectiveness to Him and depends on Him. All power as well as ability to do things belong to Him alone.
Man is one of the existing things and hence a creation of Allah. Like other things he is effective as far as his own work is concerned and unlike of them, he is the master of his own destiny. But Allah has in no way delegated His powers to him. Thus he has not got complete discretion.
"By the power of Allah I stand and sit".
The belief that any being, whether man or a being other than man, has a complete discretion, amounts to believing that being to be a partner of Allah as far as independence of activity is concerned. As independence in activity amounts to independence in essence it is contrary to Allah's unity of essence, what to say of His unity of work.
"All praise is due to Allah who has taken no spouse nor a child. He has no partner in His sovereignty, nor has He a helper to help Him out of weakness. Therefore glorify Him a great deal." (Surah Bani Isra'il, 17:111)
The three degrees of monotheism mentioned above are theoretical and a matter of creed. They are to be recognized and acknowledged. But the unity in worship is a practical matter. It is a form of 'being' and 'becoming'. The above degrees of monotheism involved right thinking. This degree is the stage of becoming righteous. The theoretical stage of monotheism means to have a perfect view. The practical stage of it means to move forward to attain perfection.
The theoretical monotheism means to comprehend the Divine oneness and the practical monotheism means man's becoming one. The theoretical monotheism is the stage of seeing and the practical monotheism is the stage of going. Before we further explain the practical monotheism, it is necessary to mention one more point about the theoretical monotheism. The question is whether it is possible to know Allah together with the unity of His essence, the unity of His attributes and the unity of His work, and if possible, whether such a knowledge is conducive to human weal and bliss; or out of the various degrees and stages of monotheism it is only practical monotheism that is useful.
As far as the possibility of gaining such a knowledge is concerned, we have discussed this problem in our books, Principles of Philosophy and the Method of Realism. As far its being useful or otherwise, that depends on our own conception of man and his weal and bliss. The modern wave of materialistic thinking has induced even the believers in Allah to consider the questions related to His knowledge to be of little use. They regard such questions as a kind of mental exercise and an escape from the practical problems of life. But a Muslim who believes that the reality of man is not his physical reality alone, but his true reality is his spiritual reality and that the essence of human spirit is the essence of his knowledge, sanctity and purity, knows well that the so called theoretical monotheism, besides being the basis of practical monotheism, is in itself a psychological perfection of the highest order. It uplifts man, leads him towards the Divine Truth and makes him perfect.
"To Him good words ascend and the pious deeds does He exalt." (Surah al-Fatir, 35:10)
Humanity of man depends on his knowledge of Allah.
Man's knowledge is not something separate from him. The more man attains knowledge of the universe, its system and its source, the more will develop his humanity, the 50% substance of which consists of knowledge.
From the point of view of Islam, especially the Shi'ah doctrine, there is not the least doubt that the attainment of the knowledge of Allah, irrespective of its practical and social effects, is in itself a goal of humanity.
Now we take up the question of practical monotheism:
Practical monotheism or unity in worship means to worship Allah alone. In other words to be single-minded in respect of the worship of Allah. Later we will explain that from the viewpoint of Islam, worship has a number of degrees. The most clear degree of it is the performance of the rites related to glorification and exaltation of Allah. The performance of such rites in respect of anyone other than Allah, means total exit from the pale of Islam. Anyhow, from the viewpoint of Islam worship is not confined to this degree alone. Every form of spiritual orientation and accepting something as one's spiritual ideal is included in worship. The Holy Qur'an says:
"Have you seen him who has chosen for his god his own lust?" (Surah al-Furqan, 25:43)
He who obeys someone whom Allah has not allowed to be obeyed and submits to him totally, worships that person: "They have taken their rabbis and their monks as their lords besides Allah." (Surah at-Tawbah, 9:31)
"And similarly none of us shall take others as our lords besides Allah." (Surah Ale Imran, 3:64)
Thus practical monotheism or unity in worship means to accept Allah alone as fit to be obeyed unconditionally, regard Him alone as one's ideal and the direction of one's conduct and to reject all others and consider them to be unfit to be obeyed unconditionally or regarded as one's ideal. Practical monotheism means to bow to Allah alone, to rise for Him, to live for him and to die for Him.
"(Prophet) Ibrahim said: I have set my face earnestly to Him who has created the Heavens and the earth. I am not a pagan. My prayers and my sacrifice, my living and my dying all are for Allah, the Lord of the universe. He has no partner. So have I been commanded, and I am the first to submit to Him."(Surah al-An'am, 6:79 & 163- 164)
This monotheism of Prophet Ibrahim is the practical monotheism. This is what the creed, 'There is no god but Allah", visualizes.