Tawheed (The oneness of Allah) Islamic Monotheism 

Tawheed is the most important Islamic belief. It implies that everything in existence originates from the one and only Creator, who is also the Sustainer and the sole Source of Guidance. This belief should govern all aspects of human life. Recognition of this fundamental truth results in a unified view of existence which rejects any divisions of life into religious and secular. Allah is sole source of Power and Authority, therefore entitled to worship and obedience from mankind. There is no scope for any partnership with the Creator. Tawhid tells man that Allah is not born, nor is anyone born of Him. He has no son or daughter. Human beings are His subjects.

Linguistically Tawheed means: "To make something one, or to assert the oneness of something." [Lisaan ul-'Arab (3/450) of Ibn Mandhoor and also al-Hujjah fee Bayaanil-Mahajjah (1/305) of Abul-Qaasim al-Asbahaanee] However, what we are concerned with here is the Sharee'ah or technical meaning of Tawheed, which is: "To single out Almighty God alone for worship." [Ad-Dururus-Sunniyyah (1/48) of Shaykh 'Abdur- Rahmaan ibn Hasan]

Literally Tawheed means "unification" (making something one) or "asserting oneness", and it comes from the Arabic verb (wahhada) which itself means to unite, unify or consolidate. However, when the term Tawheed is used in reference to Allaah (i.e. Tawheedullaah), it means the realizing and maintaining of Allaah's unity in all of man's actions which directly or indirectly relate to Him. It is the belief that Allaah is One, without partner in His dominion and His actions (Ruboobeeyah), One without similitude in His essence and attributes (Asmaa wa Sifaat), and One without rival in His divinity and in worship (Ulooheeyah 'Ebaadah). These three aspects form the basis for the categories into which the science of Tawheed has been traditionally divided. The three overlap and are inseparable to such a degree that whoever omits any one aspect has failed to complete the requirements of Tawheed. The omission of any of the above mentioned aspects of Tawheed is referred to as "Shirk" (lit. sharing); the association of partners with Allaah, which, in Islamic terms, is in fact idolatry.