Yes I know it's difficult. Muslims are so brainwashed about not departing from Islam. Fear of death or of being disowned by family. However, now more Muslims are leaving Islam...some have dreams about Jesus and become Christians.
And lately some Muslims are recognizing the evil and violence of their prophet, and they leave Islam.
Some Christian apologists use the "Islamic dilemma"....Quran affirms previous Scriptures (ours). But then Quran denies the crucifixion of Jesus Christ for our sins, denies Jesus is the Son of God.
Most converts to Islam are given a sanitized version of Islam. Some Western women converts get a rude awakening when they find out about wife beating allowed, woman's testimony is worth half of a man's and more. Also, a woman or a dog passing in front of a Muslim man will invalidate his prayer!
It's just that your understanding is the same as their misunderstanding..
Jesus made it clear that he was sent by the Father, and the Koran continues this saying that Jesus was sent by God and that he was a prophet.
The Koran you are talking about denies the Son of God of Jesus, because that book is not a Bible,
It says that the God has never been begotten by anyone, nor does He beget anyone,
It was Mary who gave birth to Jesus, not Mary who gave birth to Jehovah.
Just as God has declared, I exist by myself, I exist forever.(I am that I am, I will be what I will be.)
This may involve a different understanding of the doctrine of the Trinity.
Mohammed left only the Koran, and if the Hadith is a doctrine, it must be wrong and man-made, like some of the wrong teachings of Christianity.
Much love in Christ.