It provides them with everything they need to know and all the secrets in the world that will help them succeed and go to heaven.
Quran is the reald God words revelation to prophet Muhammad (PBUH) through the angel Gabriel (Jibril). Hence Quran includes all God commands for Muslims on what to do and what not to do. Quran also...
By following Instructions and guides and morals teachings as given by God in Quran. Refer to questions below.
That there is only one God.
Belief and faith