1-Believe in Allaah:
It is to believe in the existence of Allaah, Exalted and Glorified be He, and believe in the Oneness of His Lordship and Divinity.
One will be Muslim through acknowledging that pillar and proclaiming (Laa ilaaha il-la Al-lâh wa Anna Muhammadan Rasool-ul-Al-lâh):
Tawheed Ar-Rububiyyah (Oneness of the Lordship of Allaah):
It is to acknowledge the existence of Allaah The Almighty and single Him out in His actions, such as creation, provision, sovereignty, bestowing gifts, kingdom, fashioning, giving, withholding, benefiting, harming, giving life and death, perfect arrangement, Qadaa’ (Divine Decree) and Al-Qadar (Divine Pre-ordainment). Allaah The Almighty says:
{Allaah is the Creator of all things.}[Az-Zumar: from the verse 62]
It is to Affirm that which Allaah has affirmed for Himself or that His Messenger, peace and blessings be upon him, has affirmed of His Beautiful Names such as Al-Hayy (the Ever-Living) and Al-Qayoom (the Sustainer of all existence). Allaah The Almighty says:
{Allaah- there is no deity except Him, the Ever-Living, the Sustainer of [all] existence}[Al-Baqarah: 255]
And Ar-Rahmaan (The Most Beneficent) and Ar-Raheem (The Most Merciful). Allaah The Almighty says: {[All] praise is [due] to Allaah, Lord of the worlds. The Most Beneficent, the Most Merciful.} [Al-Faatihah: 2-3]
And the Sublime Attributes, such as knowledge. Allaah The Almighty says: {And they encompass not a thing of His knowledge.} [Al-Baqarah: 255]
And Seeing and Hearing. Allaah The Almighty says: {There is nothing like unto Him, and He is the Hearing, the Seeing.} [Ash-Shoora: 11]
And Highness. Allaah The Almighty says: {Exalt the name of your Lord, the Most High.} [Al-A‘la: 1]
He The Almighty also says: {They fear their Lord above them, and they do what they are commanded.} [An-Nahl: 50]
It is to affirm and acknowledge to Allaah The Almighty its sound meanings and indications and be aware of its effects and prerequisites in the creation.
It is to deny that which Allaah The Almighty has denied Himself or that His Messenger, peace and blessings be upon him, has denied. Allaah The Almighty says:
{Say, "He is Allaah, [who is] One, Allaah, the Eternal Refuge. He neither begets nor is born, Nor is there to Him any equivalent.}[Al-Ikhlaas: 1-4]
Ar-Rabb is the one who is worshiped and the owner who has full authority over His property. Our Rabb is Allaah who created us and created all the creation from nothing. He raises us and all worlds with His blessings. He is the Lord of all things, their owner and Who has authority over them. All affairs are determined by Him, all types of good are in His Hand and all affairs belong to Him.
Intellect has proved the existence of Allaah The Almighty and that he is unique in His Lordship and that He has perfect power over all creatures and control them. This is done by contemplating and thinking about the signs of Allaah The Almighty that indicate Him such as contemplating His sings in creating the human soul. Allaah The Almighty says: {And in yourselves. Then will you not see?} [Ath-Thaariyaat: 51]
He The Almighty also says: {And [by] the earth and He who spread it.} [Ash-Shams: 7]
If one contemplates himself thoughtfully and the miraculous creation of Allaah The Almighty, then this will guide him to the idea that he has a Lord and Creator who is Ever-Wise and Well-Acquainted. Indeed, no one can create the Nutfah (a sperm-drop) from which he was created, or change it to a clot, or change the clot to a lump of flesh, or change the lump of flesh to bones, or cover the bones with flesh.
Contemplating the signs of Allaah The Almighty in creating the universe. Allaah The Almighty says: {We will show them Our signs in the horizons and within themselves until it becomes clear to them that it is the truth. But is it not sufficient concerning your Lord that He is, over all things, a Witness?} [Fussilat: 53]
He The Almighty also says: {And of His signs are the night and day and the sun and moon.} [Fussilat: 37]
So whoever considers this universe carefully and whatever therein of the sky that contains stars, planets, sun and moons, the land that has mountains, sand, trees, seas and rivers and that he is operated in such perfect delicate system, then this will indicate that there is a creator and originator for this universe who manages its affairs. Allaah The Almighty says: {Or were they created by nothing, or were they the creators [of themselves]? Or did they create the heavens and the earth? Rather, they are not certain.} [At-Toor: 35-36]
It cannot be imagined that such creation that has such perfection in arrangement is aimless and purposeless for this will necessitate that it was created for sport and uselessly. In fact, such conclusion is invalid and thus all is based on it is also invalid. Allaah The Almighty says: {And We did not create the heaven and earth and that between them in play.} [Al-Anbiyaa’: 16]
He The Almighty explained that He did not created creation uselessly and without any purpose; rather, He created them for a great wisdom. His wisdom prevents Him The Almighty from leaving them without obligations, rewards and punishments.
Accordingly, the Eemaan of the slave cannot be sound nor can his monotheism be achieved except if he believes in the Lordship of Allaah The Almighty. However, such kind of monotheism cannot save one from the punishment of Allaah The Almighty as long as the slave does not fulfill its prerequisite namely, Tawheed Al-Uloohiyyah (Oneness of the Divinity of Allaah). Therefore, Allaah The Almighty says: {And most of them believe not in Allaah except while they associate others with Him.} [Yoosuf: 106], meaning that most of them do not acknowledge Allaah The Almighty as their Lord, Creator, Provider and Manager of their affairs, all of such matters are included in the Tawheed Ar-Ruboobiyyah, except while they associate others with Him in worship such as idols and images that cannot bring benefit or cause harm, and cannot give or withhold.
Rather, polytheists during the time of the Prophet, peace and blessings be upon him, acknowledged Allaah The Almighty as a Lord, Creator, Provider and Manager of their affairs. Their polytheism was in worship for they took peers and associates to call upon them, seek their help and ask them to fulfill their needs and requests. Allaah The Almighty says: {If you asked them, "Who created the heavens and earth and subjected the sun and the moon?" they would surely say, "Allaah." Then how are they deluded?} [Al-‘Ankaboot: 61]
He The Almighty also says: {And if you asked them, "Who sends down rain from the sky and gives life thereby to the earth after its lifelessness?" they would surely say "Allaah." Say, "Praise to Allaah"; but most of them do not reason.} [Al-‘Ankaboot: 63]
He The Almighty also says: {And if you asked them who created them, they would surely say, "Allaah." So how are they deluded?} [Az-Zukhruf: 87]
He The Almighty also says: {Say, [O Muhammad], "To whom belongs the earth and whoever is in it, if you should know?" They will say, "To Allaah." Say, "Then will you not remember?" Say, "Who is Lord of the seven heavens and Lord of the Great Throne?" They will say, "[They belong] to Allaah." Say, "Then will you not fear Him?" Say, "In whose hand is the realm of all things - and He protects while none can protect against Him - if you should know?" They will say, "[All belongs] to Allaah." Say, "Then how are you deluded?"} [Al-Mu’minoon: 84-89]
Polytheists did not believe that the idols are the power that send down rain, provide the world and manage its affairs; but rather, they believed that all of such things are from the characteristics of the Lord The Almighty. Moreover, they acknowledged that their idols that they call besides Allaah The Almighty are just created beings and possess not for themselves and their worshipers any harm or benefit and possess not power to cause death or life or resurrection. They do not hear or see. They believed that Allaah The Almighty is the only One Who can do all of such things and has no associate, and they and their idols have nothing to do with that. Alalh is the creator and all others than Him are mere created beings. He is the Lord and all others than Him are slaves to the Lord. But despite this they still attributed to Him partners and mediators from His creation. They believed that these creatures could intercede for them and bring them closer to Allaah The Almighty. Therefore, Allaah The Almighty says:
{And those who take protectors besides Him [say], “We only worship them that they may bring us nearer to Allaah in position.”}[Az-Zumar: 3], meaning intercede for them with Allaah The Almighty to support, provide and help them in what afflicts them in the worldly life.
Tawheed Al-Uloohiyyah (Oneness of the Divinity of Allaah):
It is to single out Allaah The Almighty with the action of the slaves that they do to draw near to Him (acts of worship) such as supplication, vowing, sacrifice, trust, fear and so on. Allaah The Almighty says: {That is from what your Lord has revealed to you, [O Muhammad], of wisdom. And, [O mankind], do not make [as equal] with Allaah another deity, lest you be thrown into Hell, blamed and banished.}[Al-Israa’: 39]
He The Almighty also says: {They have certainly disbelieved who say, "Allaah is the Messiah, the son of Mary" while the Messiah has said, "O Children of Israel, worship Allaah, my Lord and your Lord." Indeed, he who associates others with Allaah- Allaah has forbidden him Paradise, and his refuge is the Fire. And there are not for the wrongdoers any helpers.}[Al-Maa’idah: 72]
Tawheed Al-Uloohiyyah is the greatest, most perfect, best and most necessary principle ever for the goodness of humanity. It is for which Allaah The Almighty has created mankind and jinn. He The exalted created all creatures and prescribed rulings to establish it. With it goodness will exist and without it evil and corruption will prevail. Therefore, this category of Tawheed was the main object, sublime aim and basic element of the Da‘wah (call) of all Messengers, peace be upon them. Allaah The Almighty says: {And We certainly sent into every nation a messenger, [saying], “Worship Allaah and avoid Taghut.”}[An-Nahl: 36]
He The Almighty also says: {And We sent not before you any messenger except that We revealed to him that, "There is no deity except Me, so worship Me."} [Al-Anbiyaa’: 25]
It is the core of the argument between the prophets, peace be upon them, and their peoples. Prophets call them to the worshiping Allaah The Almighty alone and dedicating worship solely for Him in all sincerity. However, all peoples insisted on adopting Shirk and worshiping idols except those whom Allaah The Almighty has guided.
‘Ibaadah (Worship)is all words and actions that Allaah The Almighty has enjoined us to do for Him. So it is a comprehensive word which includes all word and deeds that Allaah loves and is pleased with, both outward and inward.
It is for which Allaah The Almighty has created all creatures. He The Almighty says: {And I did not create the jinn and mankind except to worship Me.}[Ath-Thaariyaat: 56]]
He The Almighty also says: {O mankind, worship your Lord, who created you and those before you, that you may become righteous -}[Al-Baqarah: 21]
He The Almighty also says: {Worship Allaah and associate nothing with Him.}[An-Nisaa’: 36]
It has many types. Amongst them are: Du‘aa’ (Supplication)
Allaah The Almighty also says: {So invoke Allaah, [being] sincere to Him in religion, although the disbelievers dislike it.}[Ghaafir: 14]
He The Almighty also says: {And [He revealed] that the Masajids (Mosques) are for Allaah, so do not invoke with Allaah anyone.}[Al-Jinn: 18]
Isti‘aathahmeans seeking refuge and protection from any harm. Allaah The Almighty says: {Say, "I seek refuge in the Lord of daybreak. From the evil of that which He created}[Al-Falaq: 1-2]
He The Almighty also says: {Say, "I seek refuge in the Lord of mankind, The Sovereign of mankind. The God of mankind, From the evil of the retreating whisperer -}[An-Naas: 1-4]
Istighaathah means seeking help to be saved from a difficulty and destruction.
Allaah The Almighty says: {[Remember] when you asked help of your Lord, and He answered you.}[Al-Anfaal: 9]
Sacrifice. Allaah The Almighty says: {Say, "Indeed, my prayer, my rites of sacrifice, my living and my dying are for Allaah, Lord of the worlds.} [Al-An‘aam: 162]
He The Almighty also says: {So pray to your Lord and sacrifice [to Him alone].}[Al-Kawthar: 2]
‘Ibaadah can be done by heart such as fear and hope or by tongue such as Du‘aa’, Tasbeeh (glorification of Allaah The Almighty), reciting Quran, or by limbs such as prayer.
It has two conditions:
1- Dedicating these deeds sincerely and solely for the sake of Allaah The Almighty. Allaah The Almighty says: {And they were not commanded except to worship Allaah, [being] sincere to Him in religion.} [Al-Bayyinah: from the verse no. 5]
2- Keenness to follow the example and guidance of the Messenger of Allaah, peace and blessings be upon him. Allaah The Almighty says: {And whatever the Messenger has given you - take; and what he has forbidden you - refrain from.}[Al-Hashr: 7]
God is the one who is worship. The truthful god is the one who is attributed by all perfect characteristics and miraculous abilities, who is able to do all things, and who has no defect or shortcoming. This rank can never be attained by one of the created being because every created being whatever his great status is, is definitely weak and imperfect. Consequently, this necessitates that none should be worshiped except Allaah The Almighty and none can be the lord except Allaah The Almighty.
What can nullify Tawheed (Monotheism) or contradict with its perfection:
Every Muslim individual should avoid all what may distort his Tawheed of the words or the actions that can destroy or decrease it. One should be aware of all of such thing, especially what may nullify or eradicate it completely. Amongst such nullifications are:
1- Shirk: It has two categories
Firstly, Shirk Akbar: It is to establish equality between others than Allaah and Allaah regarding the matters that are special attributes of Allaah The Almighty alone. It takes one out of the fold of Islam and renders all of his deed futile, and the eternal existence in the Hellfire for the one who died upon it. Allaah The Almighty says: {Indeed, Allaah does not forgive association with Him, but He forgives what is less than that for whom He wills. And he who associates others with Allaah has certainly fabricated a tremendous sin.}[An-Nisaa’: 48]
He The Almighty also says: {Indeed, association [with him] is great injustice."}[Luqmaan: 13]
He The Almighty also says: {And it was already revealed to you and to those before you that if you should associate [anything] with Allaah, your work would surely become worthless, and you would surely be among the losers."}[Az-Zumar: 65]
He The Almighty also says: { Indeed, he who associates others with Allaah- Allaah has forbidden him Paradise, and his refuge is the Fire. And there are not for the wrongdoers any helpers.}[Al-Maa’idah: 72]
This kind of Shirk has also two categories:
A-Shirk of Ruboobiyyah: It is to establish equality between others than Allaah and Allaah regarding the matters that are special attributes of Allaah The Almighty alone or attributing something of it to others than Him such as creation, provision, giving life and death, managing the matters of this universe and the like. Allaah The Almighty says: {Is there any creator other than Allaah who provides for you from the heaven and earth? There is no deity except Him, so how are you deluded?} [Faatir: 3]
Or establishing equality between others than Allaah and Allaah The Almighty regarding something of His Names and Attributes. Allaah The Almighty says: {There is nothing like unto Him, and He is the Hearing, the Seeing.}[Ash-Shoora: 11]