One of the essential characteristics of the religion of Islam is its insistence that when a people recognize Allah Most High as 'sovereign' (al-Malik) then they must ensure that the State and all its institutions submit to Allah's supreme authority and supreme law. If the State, rather than Allah, is recognized as sovereign, and that is the essence of the secularism, Islam declares such to be Shirk (blasphemy) and that is the greatest sin possible.

Around the world today the modern secular State is universally recognized as sovereign.  Its authority is recognized as supreme, and so too its law.  And so, around the world today mankind is now embraced by a universal political Shirk (blasphemy).  This is, in fact, one of the major signs that we now live in the age of Dajjal, the false Messiah or Anti-Christ, who deceived mankind into worshipping other than Allah Most High. He, Dajjal, is the mastermind behind today's world order about which the Hadith declares that 999 out of every 1000 will enter into the hellfire. But even Muslims seem to be unaware of this.