“He has prescribed for you the religion which He enjoined upon Noah and which We revealed to you (O Muhammad), and which We enjoined upon Abraham and Moses and Jesus, commanding: ‘Establish this religion and do not split up regarding it….’”
(The Qur’ān – 42:13)
The ayah throws important light on Dīn (religion) and its aim.Lexically, the word shara’a (ordained for you) implies appointing a way, a code and a rule. This divine legislation is the logical result of the fundamental truth that Allah alone is the Owner of everything in the Universe, and He alone is man’s real Guardian and it is for Him to judge the disputes that arise between human beings. Now, when Allah alone is the Owner and Guardian and Ruler, inevitably He alone is entitled to make the code of law for man and it is His responsibility that He should give this code of law to man. So, He has carried out His responsibility by revealing the Qur’ān.
The Prophets were given this legislation pertaining to Dīn, with the express instruction: Aqim-ud-din; “Establish this Dīn”, or “Keep this Dīnestablished”. Their first duty was to establish this Dīn wherever it was not established, and the second that they should keep it established after they had established it, or had found it already established in a place. Obviously, a thing can be kept established only when it has already been established, otherwise the primary requirement would be to establish it first, and then make continuous effort to keep it established.