Qur'anic verses - Unity of religion:

The unity of religion is based on the belief in the Oneness of God. The implication of this is that there can be no contradiction, or fundamental differences in the religion. Because Muslims believe in the Oneness of God, the unity of mankind, and the unity of religion, they believe in all Messengers and Revelations of God without discrimination. God said:

Say: We believe in God, and in what has been revealed to us and what was revealed to Abraham, Isma'il, Isaac, Jacob, and the Tribes, and in (the books) given to Moses, Jesus, and the Prophets, from their Lord: We make no distinction between one and another among them, and to God do we bow our will.
[Qur'an 3:84]