All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Anyone who denies dividing Tawheed into three categories and likens it to the Trinity must be ignorant and has probably deviated from the right path.
This division is known by examining the texts of the Quran and the Sunnah and inferring their meaning. It is a clarification of the meaning of Tawheed which is attributing to Allaah The Almighty all that is related to Him and the rights that are due to Him. It is not a division of the divine essence like the Christians who claim that God is the third of three and that the three are one; a matter which is illogical because how can three be one and how can one be three? Only a truly ignorant person would equate the division of Tawheed and the Trinity.
Some scholars divided Tawheed into two categories: Tawheed Ar-Ruboobiyyah and it is called the Tawheed of knowledge and affirmation, and Tawheed Al-Uloohiyyah and it is called the Tawheed of purpose and intent (dedicating one’s acts of worship to Allaah alone and seeking only His pleasure).
The aforementioned division was reported by Ibn Abi Al-‘Izz, the Hanafi scholar who further mentioned that Tawheed of knowledge and affirmation is to affirm the reality of the essence of Allaah The Almighty, His attributes, His actions and His names. There is nothing like Him. He Said so about Himself and His messenger, sallallaahu ‘alayhi wa sallam , also said the same about Him. Likewise, the Quran asserts it explicitly at the beginning of Chapters Al-Hadeed (Ch. 57), Taha (Ch. 20), As-Sajdah (Ch. 32), Aal-‘Imraan (Ch. 3), the whole of Chapter Al-Ikhlaas (Ch. 112), and at the end of Chapter Al-Hashr (Ch. 59), as well as in other places.
The Tawheed of purpose and intent is demonstrated in Chapter Al-Kaafiroon (Ch. 109), the beginning and the end of Chapter Az-Zumar (Ch. 39), the beginning, middle and end of Chapter Yoonus (Ch. 10), the beginning and the end of Chapter Al-A‘raaf (Ch. 7), the whole of Chapter Al-An‘aam (Ch. 6), and in Chapter Aal ‘Imraan where Allaah The Almighty Says (what means): {Say, "O People of the Scripture, come to a word that is equitable between us and you - that we will not worship except Allaah and not associate anything with Him and not take one another as lords instead of Allaah.” But if they turn away, then say, "Bear witness that we are Muslims [submitting to Him]."} [Quran 3:64]
Those who hold this opinion included Tawheed Al-Asmaa’ wa's-Sifaat (the oneness of Divine names and attributes) under Tawheed Ar-Ruboobiyyah (the oneness in Lordship). Those who dealt with Tawheed Al-Asmaa’ wa's-Sifaat as a separate category did so because of its importance, since many deviant sects such as the Mu‘tazilah, Ashaa‘irah and Mufawwidhah have gone astray when trying to understand this kind of Tawheed. Some scholars place Tawheed Al-Haakimiyyah (the oneness of Judicature) in a category of its own although it is a part of Tawheed Ar-Ruboobiyah because there are many people who contend against Allaah The Almighty in this kind of Tawheed in our age. For example, members of legislative councils and those who enact man-made laws.
There is abundant evidence supporting this division. The evidence for Tawheed Ar-Ruboobiyah and Tawheed Al-Uloohiyyah has been mentioned by Ibn Abi Al-‘Izz . The evidence of Tawheed Al-Asmaa’ wa's-Sifaat is the verse (which means): {Nothing is like unto Him and He is the Hearing, the Seeing.} [Quran 42:11] The evidence for Tawheed Al-Haakimiyyah is the verse (which means): {Legislation is not but for Allaah.} [Quran 12:40]
All these kinds of Tawheed overlap. Tawheed Ar-Ruboobiyyah includes Tawheed Al-Asmaa’ wa's-Sifaat and Tawheed Al-Haakimiyyah; Tawheed Al-Uloohiyyah includes Tawheed Ar-Ruboobiyyah, as mentioned by Ibn Abi Al-‘Izz . Tawheed Al-Uloohiyyah includes Tawheed Ar-Ruboobiyyah but not the other way around. The one who is unable to create is disabled, and the disabled one is not fit to be a god. Allaah The Almighty Says (what means):
• {Do they associate with Him those who create nothing and they are [themselves] created?} [Quran 7:191]
• {Then is He who creates like one who does not create? So will you not be reminded?} [Quran 16:17]
Tawheed Ar-Ruboobiyyah necessitates Tawheed Al-Uloohiyyah. Ibn Abi Al-‘Izz mentioned that Allaah The Almighty affirms Tawheed Ar-Ruboobiyyah and clarifies that there is no Creator but Him and that necessitates that He alone must be worshipped. Consequently, Tawheed Ar-Ruboobiyyah is evidence for Tawheed Al-Uloohiyyah, for the polytheists accept the first category of Tawheed but argue about the second. Therefore, Allaah The Almighty clarifies that as long as they know that there is no creator except Allaah The Almighty who brings benefits and wards off harm from His slaves without any partner, why then do they worship other than Him and ascribe partners to Him? Allaah The Almighty Says (what means): {Say, [O Muhammad], "Praise be to Allaah, and peace upon His servants whom He has chosen. Is Allaah better or what they associate with Him?" [More precisely], is He [not best] who created the heavens and the earth and sent down for you rain from the sky, causing to grow thereby gardens of joyful beauty which you could not [otherwise] have grown the trees thereof? Is there a deity with Allaah? [No], but they are a people who ascribe equals [to Him].} [Quran 27:59-60]
Allaah Knows best.