And this Qur'an which has been revealed to me to warn you...
And this Qur'an which has been revealed to me to warn you therewith and whomever it may reach..." Holy Quran (6:19) Islam has to be everlasting, because it is the last of the religions and completes the divine message, as an expression of Allah's kindness and mercy to His creatures. Throughout history and in every period mankind has not been able to do without religion.
It has always been in need of a religion to guide it, and in need of a faith to save it from ignorance, the domination of despots, and deviant ways of life. Allah the Exalted willed that the religion, which was to accompany mankind in its forward progress and to encompass the aspects of renewal and growth in life, should be Islam, because it is the religion designed to throw light on straightest path. and to guide humanity towards good and righteousness.
How wonderfully Imam Au (a.s.) describes this eternal religion and the most practical system that had been revealed to the final messenger, Muhammad (s.a.w.), saying: "...then He revealed to him the Book, a light whose brilliance never goes out, a glow which never fades away, an ocean that is never fathomed, a path that never goes astray, and a ray whose light never becomes dark." (4) Imam Ja'far al-Sadiq (a.s.) illustrates this everlasting and ever extending divine law in his saying: "The Qur'an is not dead; it is alive.
It goes on as do the day and the night, and the sun and the moon. It will be with our last as it had been with our first"(5). Imam al-Baqir (a.s.) further explicitly adds to the horinzon of that idea, and fills dimensions with light, by saying: "The Qur an is not dead, but alive, and the verse is not dead, but alive. Had it been that if a verse revealed to a people died with the death of those people, the Qur'an would have died too.
But the verse flows on with the survivors as it had flowed with the departed. "(6) Through these firm, expressive words, the leaders of thought and the Imams of the divine law, illustrate the continuity and eternality of the Islamic religion. They made a distinction between the contents and the goals of the religion on one hand, and the elements of time and place, on the other hand, since the laws and the regulations of the religion are regarded eternally applicable, free of any outside effects.