In contrast to the postmodern worldview where there is no objective truth/reality or authority, Islam clearly states there is one and only one legitimate authority- God.
The foundation of Islamic thought is Tawhid or the oneness of God. This term is sometimes misunderstood as there being one numerical God, but in reality, the concept of Tawhid is much deeper. Tawhid in Islam is fundamental, and the core of the Islamic worldview.