In Islam, a believer is a person who has faith in God and His messenger, Muhammad. A believer is a Muslim, and is expected to follow and live according to the Quran and the Sunnah of the prophet Muhammad.

There are many things that you should remember about Islam, the most important of which is that God and His messenger, Muhammad, are the only true and valid source of religious knowledge and religious law. The Quran is the only book that is sacred and is the final law of the universe. It is the only book that has the power to change people's lives and guide them to the right path.