Question:

What is the definition of Tawheed and what are its types?

The Answer:

The comprehensive definition of Tawheed comprising all of its types is: (a) The knowledge and belief of the servant, his acknowledgement and his faith in His Lord being singled out with every attribute of perfection, and his uniqueness in that (b) and the belief that there is no partner (shareek) or like (matheel) for Him in His perfection and (c) [the belief] that He holds (the right) of Uloohiyyah (devotion, worship) and Uboodiyyah (worship, servitude) over all of His creation. Thereafter, to single Him out with the types of worship.

Hence, the three types of Tawheed enter into this definition, the first of them is Tawheed al-Ruboobiyyah, which is the acknowledgement of the Lord being singled out in creating (khalq), providing (rizq), regulating (tadbeer) and nurturing (tarbiyyah). The secondd, Tawheed ul-Asmaa wal-Sifaat, which is to affirm everything that Allaah affirme for Himself or His Messenger Muhammad (sallallaahu alayhi wasallam) affirmed for Him, of beautiful names, and whatever attributes (are indicated) by these names, without resembling or likening them (to those of the creation), and without distorting them or denying them. The third, Tawhid ul-Ibaadah, which is to single out Allaah alone with all of the types of worship and their categories, and to make them only [for Allaah] and sincerely for Allaah without making anyone as a partner in anything from them.

So these are the categories of Tawheed, a servant cannot be a muwahhid (true monotheist) unless he holds fast to them and acts (in accordance) with them.

Source: Su'aal wa Jawaab Fee Ahimml-Muhimmaat in al-Majmoo'ah al-Kaamilah of Shaykh al-Sa'dee (3/61).