It is clear from what has preceded, that the meaning of laa ilaaha illallaah is: None has the right to be worshipped except the One [true] Deity; which is Allaah, alone, without any partner. He alone is the One Who deserves to be worshiped.
Therefore, this great kalimah implies that whatever else is worshiped besides Allaah is not a true deity that deserves to be worshiped; rather, all such deities are false. It is for this reason that many of the commands to worship Allaah are also accompanied by a [command] to negate worship along with Him. Because the worship is not correct if others are worshipped along either Him. Allah the Most High said:
“Worship Allah alone, and do not associate anything else as partners with Him.” [Soorah An-Nisa (4): 36].
Allah, the Most High also said: “Whosoever disbelieves in at-taaghoot and believes in Allaah, has grasped the most trustworthy handhold that never breaks. And Allaah is the All-Hearer, the All-Knower.” [Soorah al-Baqarah 2:256](1)
Allaah the Exalted [also] said: “We sent a Messenger to every nation ordering them to worship Allaah alone, obey Him, and make their worship purely for Him; and that they should avoid everything worshiped besides Allaah.” [Soorah an-Nahl 16:36[.
The Prophet sallallahu alaihi wasallam said: “Whoever says laa ilaaha illallaah and rejects whatever is worshiped besides Allaah, his blood and his wealth become sacred and his account is with Allaah.”(2).
Every Messenger said to his people: “O my people! Worship Allaah alone. You have none other than Him that has the right to be a deity to be worshiped.” ]Soorah aI-A’raaf 7:59[.
And there are evidences other than this. Imaam Ibn Rajab, rahimahullaah, said: “To explain this meaning and to clarify it: When a person says laa ilaaha illallaah, it means, according to him, that none has the right to be deified and worshiped except Allaah. And al-Ilaah is the One Who is obeyed and not disobeyed; due to awe and veneration of Him, and due to love, fear, hope and reliance upon Him; as well as being the One Who is asked from and is supplicated to.
And none of this is correct, except for Allaah the Mighty and Majestic.” (3).
This is why when the Prophet sallallahu alaihi wasallam said to the unbelievers of the Quraysh: Say laa ilaaha illallaah, they retorted: “Has he made all the deities into a single Deity to be worshiped i.e Allaah]. Indeed, this is something very peculiar!” ]Soorah Saad 38:5].
They [the unbelievers] understood that this kalimah rendered false the worship of any and every deity and restricted worship to just Allaah alone, and they did not want this. So it is clear that laa ilaaha illallaah, along with its requirement, implies:
That Allaah alone should be singled out with worship; and that the worship of other than Him should be abandoned. So when a person says laa ilaaha illallaah, he is proclaiming that it is obligatory to single out Allaah alone with worship, and he is [at the same time] denouncing the worship of other than Him, such as [the worship] of idols; [the dead in the] graves; the pious and righteous.
1) Imaam Ibn-Qayyim rahimahullah, said in I‘laamul-Muwaqqi’een (1/53): “At-Taaghoot is anyone concerning whom a person exceeds the limits, whether it is with regards to someone [who is pleased to be] worshipped, obeyed, or followed.”
2) Reported by Muslim (no.37).
3) Kalimatul-Ikhlaas (p.25).