Prophet Hud - 11:2
So that you may not serve other than Allah. Surely I am a warner and a bearer of glad tidings to you from Him.
The Qur'an is a warning to us not to serve or serve other than Allah:
The Cattle/6:155
And this is a blessed Book which We have sent down. So you should follow it and act righteously so that mercy may be shown to you.
The Cattle/6:156
"So do not say, "Two groups before us were given the Book, but we were ignorant of their teachings"."
The Cattle/6:157
"Nor can you say, "If the Book had been sent down to us, we would have been on a more right path than them". There has come to you a proof from your Lord, a guidance and a mercy. Who is more unjust than he who denies the signs of Allah and turns away from them? We will punish those who turn away from Our Verses with the worst of torment for their turning away."
The Women/4:165
Messengers bringing glad tidings and warnings... So that after all these messengers, people will have no excuse against Allah. Allah is Superior, Wise.
The Cattle/6:19
"Ask: "Whose testimony is the greatest?"Say: "Allah is the witness between me and you. I have been given this Qur´an to warn you and all those to whom it reaches. Do you bear witness that there is another god besides Allah?"Say: "I do not bear witness to that,"and then say: "He is the only God, and I am far from that which you associate partners with."
The Cattle/6:51
Warn with it (the Qur´an) those who are filled with the excitement of their coming before their Lord: They have no owner and no intercessor (intermediary) except Him. Perhaps they will be protected.
The Cattle/6:70
Leave those who take their religion as a pastime and are deceived by the life of this world. Remind them with this (the Qur´an) so that a person may not suffer the disastrous consequences of what he has earned. He has no Owner and intercessor except Allah. Even if he gives any ransom, it will not be accepted from him. These are the ones who suffer the disastrous consequences of what they have earned; they deserve a drink of boiling water and a painful torment because of their disbelief.
Prophet Abraham/14:52
This is a warning to the people. That they may listen to this warning and know that He is the only God, and that those who have understanding may take counsel.
The Night Journey/17:41
We have explained in the Qur´an that they may take admonition, but this only increases their hatred
The Night Journey/17:42
"Say: "If there had been other gods with him, as they claim, they would have sought a way to the Owner of the Sovereignty"."
The Companies/39:65
It has been revealed to you and those before you that if you associate partners, all that you do will be in vain and you will be of the losers.
Explained in Detail/41:6
"Say, "I am only a man like you, and it has been revealed to me that your God is one God. Turn to Him and ask forgiveness from Him. Woe to those who associate partners!"
Council/42:13
"We have established for you the religion which He commanded Noah before, and We commanded Abraham, Moses and Jesus as We commanded you: "Keep this religion true and do not differ in it."But what you call them to is too heavy for those who associate partners. Allah chooses for Himself whom He wills and guides to the truth those who turn to Him."
The Ranks/61:9
He has sent His messenger with guidance and the true religion so that He may make it superior to all religions, even if those who associate partners dislike it.
The Jinn/72:1
"Say, "It has been revealed to me that a group of the jinn listened and said:""We have heard an interesting Qur´an."
The Jinn/72:2
It guides to the truth, and we have believed in it; henceforth we will not associate anyone with our Lord.