That depends on which book you believe.

Islam talks about all of the previous prophets including Jesus, whom it says was not actually the Son of God. Whereas Christianity has the Trinity concept, Islam addresses this and means to restore the emphasis of divinity on God himself.

If someone is a Christian then of course he/she will not agree with this. But to a Muslim or even to a non-believing observer who might read the texts but not form opinions on what is true and not true, the Islamic God is the Christian God.