(1) It must satisfy the yearning of the human spirit to obtain eternal happiness.
(2) It must coincide with the conscience, which is the moral law written in man's mind.
(3) It must reveal God's true attributes.
(4) It must confirm man's reasoning that God is one.
(5) It must make very plain the way of salvation.
(6) It must reveal God Himself in books, through prophets, and in person.
Actually, the Qur'an fufills ALL of the requirements. This is why it is the fastest growing religion.