The word 'Trinity' is not mentioned in the Bible but it is in the Qur'an.
The possible Qur'anic references to the doctrine of "Trinity" are verses 4:171, 5:73, and5:116.[1]
People of the Book, do not go to excess in your religion, and do not say anything about God except the truth: the Messiah, Jesus, son of Mary, was nothing more than a messenger of God, His word, directed to Mary, a spirit from Him. So believe in God and His messengers and do not speak of a 'Trinity'—stop, that is better for you—God is only one God, He is far above having a son, everything in the heavens and earth belongs to Him and He is the best one to trust.
Those who say, "God is the Messiah, son of Mary," have defied God. The Messiah himself said; "Children of Israel, worship God, my Lord and your Lord." If anyone associates others with God, God will forbid him from the Garden, and Hell will be his home. No one will help such evildoers. Those people who say that God is the third of three are defying [the truth]: there is only One God. If they persist in what they are saying, a painful punishment will afflict those of them who persist. Why do they not turn to God and ask his forgiveness, when God is most forgiving, most merciful? The Messiah, son of Mary, was only a messenger; other messengers had come and gone before him; his mother was a virtuous woman; both ate food. See how clear We make these signs for them; see how deluded they are.
And when Allah will say, "O Jesus, Son of Mary, did you say to the people, 'Take me and my mother as deities besides Allah ?'" He will say, "Exalted are You! It was not for me to say that to which I have no right. If I had said it, You would have known it. You know what is within myself, and I do not know what is within Yourself. Indeed, it is You who is Knower of the unseen.
Furthermore, verses 19:88-93, 23:91, and 112:1-4 are relevant to the doctrine of "Trinity":
They say: "(Allah) Most Gracious has begotten a son!" Indeed ye have put forth a thing most monstrous! At it the skies are ready to burst, the earth to split asunder, and the mountains to fall down in utter ruin, that they should invoke a son for (Allah) Most Gracious. For it is not consonant with the majesty of (Allah) Most Gracious that He should beget a son. Not one of the beings in the heavens and the earth but must come to (Allah) Most Gracious as a servant.
No son did Allah beget, nor is there any god along with Him: (if there were many gods), behold, each god would have taken away what he had created, and some would have lorded it over others! Glory to Allah! (He is free) from the (sort of) things they attribute to Him!
Qur'an mentions the Trinity one God just as we believe in Christianity. The Christian Trinity: God. And his word. And his soul. This is exactly what was written by clearly in Qur'an in one verse:
1- NISA verse 171: (but Christ Jesus, son of Mary, the Messenger of Allah and his "word" was delivered to Mary and "a spirit from him").
ln this verse shows that Allah has: *self: "Messenger of God" * (word): in saying (and his) distraction conscience single absent back to God. * (Spirit) a distraction in (from) the conscience of a single absent back to God. The Christians don't say more than this.
2-certificate of Dr. shakankiri: testifies to ours such a Quran by Muslim scholars, Dr. Mohamed shakankiri, Professor of Islamic law at the University of Paris, then Professor of Islamic law at the law faculty at Ain Shams University in Cairo, said: [we know that Qur'an says about Jesus as the word of God, and his spirit , (the word of God and the spirit of God) this does not affect the Christian label any difficulty then was objecting to the Muslims, forcing them to acknowledge the divinity of Christ.
3-Who is Christ? Muslim answers that is the word of God, that is the Spirit of God. But this "word" and this "spirit" are created? Or are not created? If the spirit of God is a creature, there is no problem: Christ is God's permission.
If the spirit of God's is creature, so the Spirit of God and the word of God are creatures. So God was before the creation without a word! Without a spirit! And it is inconceivable!!]
This is the testimony of Dr. Mohamed shkankiri, was published in Al-Ahram newspaper Cairene on 26/05/1985 translated from the (historical Journal of French law and foreign) in the month of June 1981, and the translator Dr. Mohamed Badr, professor of history at the College of law the rights of Ain Shams University.
This may make sure you, my dear brother, and the testimony of the Koran and the Muslims scholars of the doctrine of the Trinity.
Is that there is one God has a self, has a word and has a spirit.
It is all of the above make sure that Koran certificate to Christians that they worship the one God and not polytheists.