1) Verily, Allaah has created the world and everything in it in order to worship Him alone. He sent the Messenger to call the people to Tawheed and the Noble Qur'aan is concerned with the aqeedah of tawheed in most of its chapters, and it explains the harm of shirk for the individual and the society. Shirk is the reason for destruction in this life and the reason for eternal destruction in the Fire of the Hereafter.

2) Verily, all the Messengers began their call with Tawheed, which they were commanded by Allaah to convey it to the people. He, the Most High, said: We have not sent before you from the Messengers, except We inspired to him that He is the only One worthy of worship, so worship Him. [21:25]

The Messenger of Allaah stayed in Makkah for thirteen years while he called his people to the Tawheed of Allaah and he called to Him alone without associating anything with Him. It was regarding this issue that Allaah revealed the following verse to His Noble Messenger: Say: Verily I call to my Lord and I do not ascribe any partners to Him at all. [72:20]

The Noble Messenger brought up his followers upon Tawheed from the time of childhood and he said to the son of his uncle, his cousin 'Abdullaah ibn 'Abbaas: "When you ask, then ask Allaah, and when you seek help, then seek help from Allaah." [Hasan Saheeh, Tirmidhi]. This Tawheed is in reality the religion of Islaam, which is built upon it, and anything other than it is not accepted by Allaah.

3) Verily, the Messenger (sallallaahu alayhi wasallam) taught his Companions to begin their call to the people with tawheed, so he said to Mu'aadh ibn Jabal, when he (sallallaahu alayhi wasallam) sent him to Yemen: "So let the first thing you call them to, be the testification that none has the right to be worshipped except Allaah." And in another narration: "...that they worship Allaah alone." [Bukhari and Muslim]

4) Tawheed is embodied in the testification that "None has the right to be worshipped except Allaah, and Muhammad is the Messenger of Allaah." Its meaning is that there is no one who is worthy of deserving worship except Allaah, and there is no worship except that which the Messenger of Allaah came with. It is this testification which allows a unbeliever to enter into Islam, since it is the key to Paradise, and the one who testifies to it and believes it enters into Paradise as long as he does not invalidate it by shirk or a word of disbelief.

5) The disbelieving Quraish offered the Messenger of Allaah (sallallaahu alayhi wasallam) kingship, wealth and wives and other than that from the pleasures of this life in exchange for him abandon the call to tawheed, and abandon the attacks against the idols. However, he did not desire that from them, rather lie continued his call and endured the onslaught along with his Companions, until the call to tawheed was victorious after thirteen years, after which Makkah was conquered and the idols were destroyed. The Messenger of Allaah (sallallaahu alayhi wasallam) recited Truth has come and falsehood has vanished, surely falsehood is ever bound to vanish. [17:81]

6) Tawheed is the preoccupation of a Muslim in his life, so he begins his life with Tawheed and he ends his life with Tawheed. It is task in life is to establish Tawheed and the call to Tawheed, since Tawheed unifies the believers and gathers them upon the statement of Tawheed.

So we ask Allaah to make the statement of Tawheed (Laa ilaaha lila Allaah) our last words in this world and we ask Him to gather the Muslims upon the statement of Tawheed.