Now that we have gone through the axiom of monotheism and accepted it as a logical and rational principle, we should note that this belief is much more complicated than it seems. In order to reach a firm belief in the existence of God and His Oneness, one has to follow each of its stages.

These degrees include “unity of the essence of Allah”, “unity of the attributes of Allah”, “unity in what Allah does” and “unity in worship”. The first three of these belong to the realm of theoretical monotheism, while the last one is among practical monotheism. Here we will have a brief look at each of these steps.

1. Unity of the Essence of Allah

This stage of monotheism is defined as believing that God is One and Unique in His essence. The very first thing that one assumes regarding Allah is that of His Self-dependence; He is a being who is not dependent on any other beings in any way, while everything depends on Him and seeks His help.

Secondly, one has to believe in His Creatorship; that He is the creator and the ultimate source of all the existing things, all things are from Him, and He is not from anything. Accordingly, He is called the First Cause. The unity of essence, thus, means that this being is not multiplicable, and there is nothing like it. Since the self-existing truth is one, then this world has only one source and one end; it has neither originated from various sources nor will return to various ones, the whole universe has one center, one pole, and orbit.

2. Unity of the Essence and Attributes of Allah

It is defined as the recognition that the essence and the attributes of Allah are identical and that His various attributes are not separate from each other. While the Unity, in essence, refers to God’s Oneness, denying the existence of any peer or like for Him, the Unity in attributes means the negation of any kind of multiplicity or plurality within His essence.

All the attributes implying perfection and beauty belong to Him, and they are not at all separate from Him. The separation of the essence from the attributes and their separation from each other are the characteristics of a limited being, while God is infinite and such characteristics cannot be ascribed to Him. Accordingly, Allah has attributes which are unlimited – like His own self – and identical with His essence.

3. Unity in What Allah Does

The Unity of His work is to recognize that the world with all its systems is the work of Allah alone and has originated from His will only. Nothing in this world has occurred on its account and independent from God; every agent, cause or power owes its existence and effect to Him.

As He has no partner in His essence, He has no peer in what He does either. While human beings, as one of these agents and causes, have control over their own actions and can influence their destiny, they are not at all out of God’s will and supervision; otherwise, we should consider them as God’s partners, which will ultimately deny God’s unity in essence.   

4. Unity in Worship

Reaching this stage is when one only worships God and has prepared himself for praying Allah, the One. Based on Islamic doctrine, the act of worship has its own degrees, the clearest of which is the performance of the rites for Allah’s glorification and exaltation.

According to Holy Quran, worship is not limited to the actual performance of prayer but includes any form of spiritual orientation and idealization; the person whose purpose and motivation in life only satisfies his own whim has, in fact, led his spiritual direction toward it and thus worshiped it instead of God. So, the unity in worship is to see Allah as the only one who is fit to be worshiped and obeyed unconditionally and regard Him as the only purpose and direction of one’s conduct.

What Is the Difference between Theoretical and Practical Monotheism?

The first three degrees are all theoretical and a matter of creed - they should be recognized and acknowledged, and require rational thinking- while the fourth one is practical and a necessity for all of our actions.

Moreover, theoretical monotheism gives an insight to perfection while practical monotheism is the actual movement toward it; it is only seeing God’s Oneness and finding knowledge about it while practical monotheism is experiencing and feeling these beliefs tangibly in all walks of life.

In other words, theoretical monotheism provides the basis and foundation of practical monotheism; on the other hand, without bringing those beliefs into action, they would become deficient and imperfect.

As other axioms, the afterlife (Ma’ad) is one of the first requisites for stepping into the religion of Islam and is defined as the existence of another world that creatures enter after their death, where they experience eternal life. It is noteworthy that the belief in receiving revelation and prophethood (Nubuwwah) builds the foundation of this axiom; in other words, one cannot find acceptance in the afterlife unless he comes to faith in prophethood and more importantly, monotheism (Tawhid).

Nevertheless, prophets didn’t come to impose the idea of Ma’ad on their followers, rather led people’s mind to ponder on this issue and recognize its validity. The reason for this concept to be considered as an axiom is that Islam not only wants us to have faith in the afterlife dependent on the belief in prophethood but also through individual and conscious investigation.

How to Find Faith in the Afterlife?

Aside from revelations that prophets received, there are some other ways and proofs for coming to believe in the afterlife which is the result of the intellectual and scientific efforts of human beings, including the knowledge of God, the universe, and human soul. Here we will briefly introduce each of these ways.

1. God’s Attributes  

This argument which is based on the axiom of monotheism (Tawhid) -God exists and is the only one and should be accepted through rational thinking -, claims that God cannot be considered perfect and wise unless we believe in the existence of a world beyond this material world, an afterlife. In other words, without afterlife, the whole creation will become meaningless and vain.

If we find a wisdom governing the universe, then it necessitates the existence of another world which complements creation and forms a part of it. But why? We justify this issue based on God’s attributes.

Divine Justice

God is just and has built the foundation of the universe, heaven, and earth on Justice. Human’s life, also, is placed within this just order; therefore, God’s justice requires every creature to be endowed with what they deserve in order to avoid denying their right.

The reward of many good deeds is not obtained in this world, just as many sins that cannot be punished thoroughly during this earthly life. Accordingly, since this world is limited and does not have the capacity to provide human beings with their deserved rewards or punishments, another world with infinite and unlimited time must exist in order to make up for the rights that people have not acquired in this world.

Divine Wisdom

Wisdom is attributed to one whose deeds are always purposeful and would result in a specific and clear goal. Therefore, the wise God does not commit any absurd or nonsensical deed, otherwise, his action would be the result of his ignorance and lack of knowledge.

Moreover, the creation will not be meaningless, if it leads to eternity; if the creatures have been created for eternity and permanent endowment from God, then it shows an existence – as opposed to nothingness, inexistence – and continuity, thus it would not be absurd.   

In addition, he has created every creature for a special purpose and has provided them with the means of reaching it. If He has endowed them with certain desires and capacities, then surely He has anticipated the appropriate answer for them, too.

For instance, in response to the urge for thirst or hunger in animals, He has created water and food in order to satisfy this need of them. Similarly, He has bestowed upon human beings the desire for immortality and eternal perfections; most of us feel the urge for eternity and unending life, as well as everything good in its best way.

If there were no way of reaching these desires, then why would God have placed them in human beings? These feelings do not fit into this earthly life and cannot be satisfied here; our All-wise God has for sure devised a plan for mankind to fulfill these needs, that is creating a world where they are able to experience everlasting life and achieve what they long for in their perfect forms.

2. Universal Phenomena

Looking around, we can find many instances that remind us of the Resurrection and the revival of human beings in the afterlife. The very first thing that comes to mind when we think about the creation of the universe, is that the same power and wisdom that has created this world also has the power and ability to create another one. When we compare this power to our own capabilities, the occurrence of the afterlife seems far-fetched, however by the omnipotent being who has brought this world into life, this act is not at all infeasible.

Moreover, we are faced with many incidents in this world, on a daily basis, which is fairly similar to what will happen in the afterlife; we have seen them so many times that we have got used to their happening and consider them typical and insignificant, however at a closer look, we can find out the systematic and repeated order that governs the universe.

We constantly experience the cycle of life and death in nature with the change of seasons, that with the coming of winter and autumn everything - trees, flowers, etc. - on earth seems to be dying, and by spring, the sky sends its drops of rain to awake the hibernating earth and bestows a new breath on it.

Considering God’s power, the afterlife thus is neither impossible to happen nor something beyond our understanding or illogical based on the events that take place in the universe.

3. Human Being’s Soul

What we as human beings consider as our “self” or “I” is in fact a fixed and permanent fact. This “I” is actually the soul in mankind which is an immaterial and unchanging reality and has every action of the body under its control.

The axiom of the afterlife cannot be accepted unless one has a belief in the existence of a soul in human beings independent of their body, which is responsible for their conscious choices and deliberate actions. Otherwise, the belief in the afterlife is not possible, since if we see human beings as only this body that would be destroyed and diminished by death, then we cannot expect them to be revived exactly as the same; the human being that will be brought to life again would be for sure a different creature.

The only valid assumption would be that when a person dies his soul continues to exist until it returns to the body. Accordingly, the issue of the afterlife is justifiable through the knowledge of the human being’s reality which leads us to consider him as an immortal and infinite being.

Furthermore, as it was mentioned above, human beings are endowed with certain capacities - desire for immortality, to have eternal perfections - which are not fully compatible with the characteristics of this world and require another world for their fulfillment. If there were no resurrection for human beings, then his creation would be pointless from the very beginning, since his perfection has not manifested itself in this world and the means of receiving this goal would become useless and in vain. 

To conclude, the aim of creation is going back toward God and to attend His final judgment among His creatures on Resurrection Day; everything in this world has been created to return to its God, reach eternity and never fail to exist.

They have come to life in order to pursue the path to their perfection and ultimately join God Almighty. It is noteworthy that the afterlife is not considered as dependent and the result of this world, but rather as a necessity and introductory for this earthly life; God has created this Universe, especially human beings with their extraordinary capacities - the power of the mind, the urge for seeking God and joining Him, etc.-, for becoming immortal in the afterlife and reaching the summit of their capabilities and eternal bliss; thus this world only provides the ground for the ultimate goal of creation. Afterlife is the final destination of creation and this world is only a temporary dwelling.