Islamic Contradiction

Islam has many contradictions but one seems to be important and not just a superficial argument. They follow gnostic Gospels vs Christian Gospels, and say John is a false Gospel. The problem is they use John 14-17 and the helper passages to say Muhammed is spoken of in the Bible, which he isn't. The passages speak of the Holy Spirit.

The problem for Islam is they use what they call false as evidence. How could John be evidence for them if it is a false Gospel in their view. If not a false Gospel then Jesus truly died, which they deny. You see the contradiction. They don't accept John but use it in support of Muhammed if it suits their narrative. Hypocrisy? Yes. A lie. Yes. Deception. Yes.