When Jesus found unbelief on their part, he said: "Who will be my helpers to (the work of) Allah?" Said the Disciples: "We are Allah's helpers: we believe in Allah, and you bear witness that-we are Muslims. 

[3: Al-Imran-52]

Ibrahim was not a Jew nor a Christian but he was (an) upright (man), a Muslim, and he was not one of the polytheists.(Surah 3:67)

MUSLIM BOOK DiSTORTED?

(As for) those who take a small price for the covenant of Allah and their own oaths-- surely they shall have no portion in the hereafter, and Allah will not speak to them, nor will He look upon them on the day of resurrection nor will He purify them, and they shall have a painful chastisement. Most surely there is a party amongst those who distort the Book with their tongue that you may consider it to be (a part) of the Book, and they say, It is from Allah, while it is not from Allah, and they tell a lie against Allah whilst they know. It is not meet for a mortal that Allah should give him the Book and the wisdom and prophethood, then he should say to men: Be my servants rather than Allah's; but rather (he would say): Be worshipers of the Lord because of your teaching the Book and your reading (it yourselves).(Qur'an 3:77-79)

Then woe to those who write the Book with their own hands, and then say:"This is from Allah," to traffic with it for miserable price!- Woe to them for what their hands do write, and for the gain they make thereby.(Surah 2:79)

MUHAMMAD DOUBT THE QURA'N?

So if you are in doubt, [O Muhammad], about that which We have revealed to you, then ask those who have been reading the Scripture before you. The truth has certainly come to you from your Lord, so never be among the doubters.(Surah 10:94)