Trinity in the Quran?

The Trinity is a triunity of the Father, Son and Holy Spirit.  But what does the Quran have to say about the Christian belief of the Holy Trinity?  Read the following verses in the Quran and determine for yourself if Allah is speaking out against the belief of the trinune God of Father, Son and Holy Spirit. 

[S. 4:171] O People of the Scripture! Do not exaggerate in your religion nor utter aught concerning Allah save the truth. The Messiah, Jesus son of Mary, was only a messenger of Allah, and His word which He conveyed unto Mary, and a spirit from Him. So believe in Allah and His messengers, and say not "Three" - Cease! (it is) better for you! - Allah is only One God. Far is it removed from His Transcendent Majesty that He should have a son. His is all that is in the heavens and all that is in the earth. And Allah is sufficient as Defender.

•  What does Allah mean by "say not Three?"  Three what...?  Three separate Gods, or three persons of the Holy Trinity or?  The People of the Scripture (Christians) do not say "Three" when referring to the Trinity.  We say "Father - Son - Holy Spirit" (a Triunity of one God...in three distinct persons yet all identical in essence) and throughout the Bible it is mentioned that there is only one God.  By Allah stating that "Allah is only One God" He is implying that Christians believe in three separate Gods  and or taking partnership with God and that is the reason Allah is telling them to believe in only One God.  
•  This passage does not represent the true understanding of the Trinity.
•  There is no mention of worshiping the Father and Holy Spirit. 
•  Who is Allah talking about here?

[S. 5:17] They indeed have disbelieved who say: Lo! Allah is the Messiah, son of Mary. Say: Who then can do aught against Allah, if He had willed to destroy the Messiah son of Mary, and his mother and everyone on earth? Allah's is the Sovereignty of the heavens and the earth and all that is between them. He createth what He will. And Allah is Able to do all things.

•  There is no verse in the Bible that says, "God is the Messiah."  Christians say that Jesus is the Messiah.
•  Allah states that he can destroy not only Jesus, but also his mother and everyone on earth.  This sounds as if Allah is stating that He is above Jesus and Mary, in the case if they are viewed as gods.
•  There is no mention of worshiping the Father and Holy Spirit.

[S. 5:70-75] We made a covenant of old with the Children of Israel and We sent unto them messengers. As often as a messenger came unto them with that which their souls desired not (they became rebellious). Some (of them) they denied and some they slew.  They thought no harm would come of it, so they were wilfully blind and deaf. And afterward Allah turned (in mercy) toward them. Now (even after that) are many of them wilfully blind and deaf. Allah is Seer of what they do.  They surely disbelieve who say: Lo! Allah is the Messiah, son of Mary. The Messiah (himself) said: O Children of Israel, worship Allah, my Lord and your Lord. Lo! whoso ascribeth partners unto Allah, for him Allah hath forbidden paradise. His abode is the Fire. For evil-doers there will be no helpers.  They surely disbelieve who say: Lo! Allah is the third of three; when there is no God save the One God. If they desist not from so saying a painful doom will fall on those of them who disbelieve.  Will they not rather turn unto Allah and seek forgiveness of Him? For Allah is Forgiving, Merciful.  The Messiah, son of Mary, was no other than a messenger, messengers (the like of whom) had passed away before him. And his mother was a saintly woman. And they both used to eat (earthly) food. See how We make the revelations clear for them, and see how they are turned away!

•  There is no verse in the Bible that says, "Allah is the Messiah."  Christians say that Jesus is the Messiah.
•  Allah mentions both Jesus and Mary were taken as two separate gods and Allah is the third of three.  This is not the true Christian Trinity.
•  Allah may be simply implying not to take partnership with Allah.
•  There is no mention of worshiping the Father and Holy Spirit.
•  Who is Allah talking about here?

 

[S. 5:116-117]  And when Allah saith: O Jesus, son of Mary! Didst thou say unto mankind: Take me and my mother for two gods beside Allah? he saith: Be glorified! It was not mine to utter that to which I had no right. If I used to say it, then Thou knewest it. Thou knowest what is in my mind, and I know not what is in Thy Mind. Lo! Thou, only Thou, art the Knower of Things Hidden?  I spake unto them only that which Thou commandedst me, (saying): Worship Allah, my Lord and your Lord. I was a witness of them while I dwelt among them, and when Thou tookest me Thou wast the Watcher over them. Thou art Witness over all things.

•  Allah mentions both Jesus and Mary were taken as two separate gods. This is not the true Christian Trinity.
•  Allah may simply be implying not to take partnership with Allah.
•  There is no mention of worshiping the Father and Holy Spirit.
•  Who is Allah talking about here? 

 

HERETICAL CHRISTIAN GROUPS:

These two groups were known for taking Mary as a god.  However, they were both very small sects and were snuffed out during the early church prior to the time of Muhammad.

• The Collyridianisms Heresy: "A heretical sect in the 4th and 5th centuries around Arabia that employed women as priestesses to offer sacrifices in the form of rolls of bread to the Virgin Mary" (Merriam-Webster Dictionary)

•  The Mariamite Heresy: Another small heretical sect where followers worshiped idols and believed that Mary was a goddess.  However very little information is knows about this sect but that they arose around Arabia.  

QUESTIONS:

When reviewing these questions, it is important to keep in mind what Allah says about his revelation to mankind.  Allah states many times that the verses are "clear" and "specific" (S. 11:1, 6:114, 16:89, and 41:3), yet other chapers are not entirely clear (S. 3:7).  

1. Why is Allah speaking so much about such a tiny sect of heretical Christians that worshiped Mary as god, when they no longer existed during the time of Muhammad?  Wouldn't it have been more clear if Allah simply said "do not worship me as the Trinity"?
2. Where in the Quran does Allah exactly say: "Do not worship the Trinity" or "Do not worship me as Father, Son and Holy Spirit"?
3. Where in the Quran does Allah say that those who believe that Allah is the Father, Son and Holy Spirit are disbelievers?
4. Where in the Quran does Allah speak against Christians who believe that God is one and three at the same time?
5. Where in the Quran does Allah define the meaning of Jesus' Sonship?
6. Where in the Quran does Allah say that it is not possible for him to enter into his own creation?
7. Do these verses clearly or unclearly represent the Trinity as Father, Son and Holy Spirit?