Muslims believe, above all else, that Allah, or God, is One without partners who share in His divinity. There are three traditional categories of Tawhid. The categories overlap, but help us to understand and purify our own faith and worship.
Tawhid Ar-Rububiyah - Oneness of LordshipMuslims believe that Allah caused all things to exist. Allah is the only One Who created and maintains all things. Allah is not in need of help or assistance in His Lordship over creation. Muslims reject any suggestion that Allah has partners who share in His actions.
On this point, the Quran says:
"Say: 'Who is it that provides you with sustenance out of heaven and earth, or who is it that has full power over [your] hearing and sight? And who is it that brings forth the living out of that which is dead, and brings forth the dead out of that which is alive? And who is it that governs all that exists?" And they will [surely] answer: "[It is] God." (10:31)
Tawhid Al-Uluhiyah/'Ebadah - Oneness of WorshipAs Allah is the sole Creator and Maintainer of the universe, it is to Allah alone that we should direct our worship. Throughout history, people have engaged in prayer, invocation, fasting, supplication, and even animal or human sacrifice for the sake of nature, people, and false dieties. Islam teaches that the only being worthy of worship is Allah (God). Allah alone is worthy of our prayers, praise, obedience, and hope.
Sometimes people do not realize that they are steering away from Tawhid al-Uluhiyah, when they invoke special charms, seek "help" from their ancestors, or make vows "in the name of" specific people. Slipping into shirk in this area is dangerous to one's faith.
Every single day, several times a day, Muslim recite certain verses in prayer. Among them is this reminder: "Thee alone do we worship; and unto Thee alone do we turn for aid" (1:5).
The Quran further says:
"Say: 'Behold, my prayer, and (all] my acts of worship, and my living and my dying are for God [alone], the Sustainer of all the worlds, in whose divinity none has a share: for thus have I been bidden -and I shall [always] be foremost among those who surrender themselves unto Him." (6:162-163)
"Said [Abraham]: 'Do you then worship, instead of God, something that cannot benefit you in any way, nor harm you? Fie upon you and upon all that you worship instead of God! Will you not, then, use your reason?'" (21:66-67)The Quran specifically mentions the excuse of those people who claim that they worship Allah, but merely seek help from intermediaries or intercessors. We are taught in Islam that there is no need for intercession, because Allah is close to us:
"And if My servants ask thee about Me - behold, I am near; I respond to the call of him who calls, whenever he calls unto Me: let them, then, respond unto Me, and believe in Me, so that they might follow the right way." (2:186)
"Is it not to God alone that all sincere faith is due? And yet, they who take for their protectors aught beside Him [are wont to say], 'We worship them for no other reason than that they bring us nearer to God.' Behold, God will judge between them [on Resurrection Day] with regard to all wherein they differ; for, verily, God does not grace with His guidance anyone who is bent on lying [to himself and is] stubbornly ingrate!" (39:3)
Tawhid Adh-Dhat wal-Asma' was-Sifat - Oneness of Allah's Attributes and NamesThe Quran is filled with descriptions of Allah's nature, often through attributes and special names. The Merciful, the All-Seeing, the Magnificent, etc. are all names which describe Allah's nature and should only be used to do so. Allah is distinct from His creation. As human beings we may strive to understand and emulate certain values, but Allah alone has these attributes perfectly, in full and in their entirety.
The Quran says:
"And God's [Alone] are the attributes of perfection; invoke Him, then, by these, and stand aloof from all who distort the meaning of His attributes: they shall be requited for all that they were wont to do!" (7:180)Understanding Tawhid is key to understanding Islam and the fundamentals of a Muslim's faith. Setting up partners with Allah is the one unforgiveable sin in Islam: "Verily, Allaah forgives not that partners should be set up with him in worship, but He forgives except that (anything else) to whom He pleases" (Quran 4:48). Learning about the different types of tawhid may help us to be aware of pitfalls and achieve success in this life and the hereafter.