O People of the Book! Commit no excesses in your religion: Nor say of Allah aught but the truth. Christ Jesus the son of Mary was (no more than) a messenger of Allah, and His Word, which He bestowed on Mary, and a spirit proceeding from Him: so believe in Allah and His messengers. Say not “Trinity” : desist: it will be better for you: for Allah is one Allah: Glory be to Him: (far exalted is He) above having a son. To Him belong all things in the heavens and on earth. And enough is Allah as a Disposer of affairs. Surah 4:171

1. Allah cannot be “one” and “three.”
2. The Trinity is never mentioned in the Bible.

The Koran claims Jesus taught against the Trinity.

Surah 4:171 seems to indicate that the word "Trinity" was around when Jesus began his ministry.  The word "Trinity" doesn't even appear in the Bible, yet the concept is very apparent.

According to the Bible, Jesus was the one who spoke of the Holy Spirit and His equal relationship with God as His Father. Jesus was viewed by the leaders of the time as a prophet/messenger, but Jesus set out to show He was God. In fact, it was the religious leaders of the time, Pharisees and scribes, who opposed the idea of Jesus being God. They were struggling with Duality, God being two persons, Father and Son.

The idea of THREE GODS wasn't even an issue when Jesus was around.  No  one would be promoting such an idea.

The Koran finds the Trinity difficult to comprehend. It calls it a lie.

They say: Allah has taken a son (to Himself)! Glory be to Him: He is the Self-sufficient: His is what is in the heavens and what is in the earth; you have no authority for this; do you say against Allah what you do not know? Say: Those who forge a lie against Allah shall not be successful. Surah 10:68-69

However, is the trinity that hard to comprehend? The Koran acknowledges the mighty power of God.

“Is not He Who created the heavens and the earth able to create the like thereof?” - Yea, indeed! for He is the Creator Supreme, of skill and knowledge (infinite)! Verily, when He intends a thing, His Command is, “be”, and it is! Surah 36:81-82

Can a God of unlimited power reveal Himself in three ways and still be one? This same God who spoke and the stars were created could certainly show himself in such an extraordinary way.

The Koran says the Trinity is a lie.  A lie suggests an ulterior motive—some sort of reason for gain. What would profit someone by claiming the Trinity to be true, especially if Allah said it was false?

So who are the “they” that the Koran says are blaspheming? Who came up with the idea of the Trinity?