Only people who have not bothered to spend any time reading any of the available religious text would imagine such to be true.
There is only One God. Muslims accept all of the messengers of God. They all brought the same message to the people "Worship God".
Jews accept: Adam, Noah, Lot, Moses, David, Abraham, Joseph, (Rejecting Jesus, and Muhammad)
Christians accept: Adam, Noah, Lot, Moses, David, Abraham, Joseph, Jesus (elevating Jesus to the position of God), (Rejecting Muhammad)
Muslims accept: Adam, Noah, Lot, Moses, David, Abraham, Joseph, Jesus (as a righteous messenger of God), and Muhammad
So we can easily simplify this equation by saying that all three faiths believe in the God of Abraham (Often termed the
Abrahamic faiths), and the tenants of Moses.
Not only this but the Quran actually clears up any remaining confusion with the following verse,
[Quran 2:62] "Those who believe (in the Qur'an), and those who follow the Jewish (scriptures), and the Christians and the Sabians,- any who believe in Allah and the Last Day, and work righteousness, shall have their reward with their Lord; on them shall be no fear, nor shall they grieve."