There should not be any doubt that books that contain divine information are cure for all problems of humanity but the quran is unique in this resepct. Why? Because this is the only book today on the surface of the earth that is direct revelation of God. Not written by people as collection of reports about divine messengers.
The kings and their priests have been active against these books and may have added their stuff in them to confuse people in order to make them their slaves and to cause conflicts and wars between people.
So we need to be very careful as to what we attribute to God in the name of these books. Even if the original texts of these books are not adulterated their interpretations certainly are.
Kings wanted God out of their way so they put in place priestly classes who did their dirty work and at least succeeded in masking the original meanings of these texts in order to justify what they wanted to do to human beings in the name of God. That is how we ended up with separation between state affairs and God affairs or church and state or religion and secularism whatever you want to call it.