The three categories of Tawhid 1.Tawhid Ar-Rububiyyah What this means to single out regarding His actions. For example, creating, providing, giving life, causing death, sending down rain, causing crops to grow. The monotheistic Muslim believes that Allah is the Creator, the Provider, the One Who brings benefit, and theOnly One Who can harm, the One Who brings to life, the One Who causes death, the King of the entire dominion - in His Hands are the reins of the heavens and the earth.
The polytheists believed in this category of Tawhid, for Allah Almighty says about them:
'Say: "Who provides for you from the sky and the earth? Or who owns hearing and sight? And who brings out the living from the dead and brings out the dead from the living? And who disposes the affairs?" They will say: "Allah." Say: "Will you not then be afraid of Allah's punishment?” (Surah Yunus 10:31) 2. Tawhid Al-Uluhiyyah This means to single out Allah with those actions that His worshippers perform as a form of worship - in ways that Allah and His Messenger (Sallallahu Alayhi wa Sallam) have legislated. It means to believe that Allah alone is the One Who deserves to be worshipped and obeyed, and that there is none that deserves to be worshipped other than Him. Therefore, all acts of worship must be performed purely for Him. So when one prays, he must pray only to Allah; when one supplicates, he must supplicate only to Him. When one slaughters an animal, it must be done by Allah's Name only. When one makes a vow, one must do it only for Allah. When one seeks help, one must seek it from Allah in those matters that only Allah is capable of. When one calls out for help, one must call out for help from Allah - in those matters that only Allah is capable of.
To believe and apply Tawhid in this sense requires one to: -
Worship none except Allah
Fear none except Allah
Submit to none except Allah
Seek refuge in none except Allah
Seek help from none except Allah
Rely upon none except in Allah
Seek judgement from none except Allah's Shari'ah
To not make lawful except that which Allah has allowed
To not make forbidden except that which Allah has prohibited
It is confirmed that 'Adi bin Hatim - who was a Christian in the Days of Ignorance - heard the Prophet (Sallallahu Alayhi wa Sallam) recite this verse:
They (Jews and Christians) took their rabbis and their monks to be their lords besides Allah, and the Messiah, son of Maryam.(Surah At-Taubah 9: 31) 'Adi said, "0 Messenger of Allah, they did not worship them." The Messenger of Allah (Sallallahu Alayhi wa Sallam) said:
"Indeed, they (the rabbis and monks) would forbid them from that which was lawful, and they would permit them to do that which was forbidden. They followed them: that was their worship of them. " The Tawhid with which the Messengers were sent Tawhid AI-Uluhiyyah is the Tawhid that the Messengers invited people to accept, and it is that category of Tawhid that people rejected, from the time of Nuh, (Sallallahu Alayhi wa Sallam), until that of Muhammad (Sallallahu Alayhi wa Sallam) Allah Almighty says:
And We did not send any Messenger before you but We inspired him (saying): "Laa Ilaha Illa Ana [none has the right to be worshipped but I], so worship Me. (Surah Al-Anbiya’ 21: 25) And Allah Almighty says:
And verily, We have sent among every Ummah (community, nation) a Messenger (proclaiming): "Worship Allah, and avoid the Taghut (all false deities) ... (Surah An-Nahl 16: 36) Whosoever worships Allah alone, leaving the worship of all else, has indeed followed the straight path, and has grasped the most trustworthy handhold:
Whoever disbelieves in Taghut and believes in Allah, then he has grasped the most trustworthy handhold that will never break. (Surah Al-Baqarah 2: 256)
"Take not Ilahain (two gods in worship, etc.). Verily, He is only One Ilah (God). Then, fear Me much.” (Surah An-Nahl 16: 51) The polytheists among the Arabs acknowledged that Allah created all things, while their gods neither created, nor provided, nor brought things to life, nor caused death; Allah Almighty says:
And indeed if you ask them, "Who has created the heavens and the earth?" They will surely say: "The All-Mighty, the All-Knower created them.” (Surah Az-Zukhruf 43: 9) Nevertheless, they were polytheists because they worshipped other gods along with Allah, gods that in their estimation were intermediaries between them and Allah. So, because they rejected Tawhid Al-Uluhiyyah, their belief in Tawhid Ar-Rububiyyah didn't benefit them at all:
And most of them believe not in Allah except that they attribute partners unto Him. ((Surah Yusuf 12: 106) They didn't single Allah out for worship, supplication and seeking help; rather, they associated partners with Him in their worship:
"We worship them only that they may bring us near to Allah.” (Surah Az-Zumar 39: 3)
"These are our intercessors with Allah.” (Surah Yunus 10: 18)
So again, it becomes clear that although one may believe in Tawhid Ar-Rububiyyah, one is a polytheist, not a Muslim, as long as one doesn't believe in Tawhid Al-Uluhiyyah.
To continue Insha Allah