This day I have perfected your religion for you and completed My favour to you.
This day I have perfected your religion for you and completed My favour to you. If we want to discuss this question from historical point of view, we should study those books which have mentioned this event, especially those written by the Sunnis. Quotations from these books can be found in the books like al-Ghadir, which was published in Mashhad a few years back and is an excellent worth-reading summary of this question.
The argument of the Shi'ah is based on the historical background of this verse. They say that they find that the phrase, 'this day' does not mean today. Then what day does it mean? When a reference is made to the occasion for the revelation of this verse, it is found that not one or two but tens of continuous reports say that this verse was revealed at Ghadir al-Khum on the day the Holy Prophet appointed Imam Ali as his successor.
(ii) Internal Evidence existing in the Verse In the verse itself there are internal indications which corroborate what is confirmed by history. The verse in question says: This day unbelievers lost all hope of ever harming your religion.
Let us compare this verse to a number of other verses which warned the Muslims and said that the believers including the People of the Book and others were always intriguing against them and loved to turn them away from their religion: "Many of the people of the Book long to make you disbelievers after your belief, through envy on their own account." (Surah al-Baqarah, 2:109) Thus we see that while several other verses of the Quran say that the disbelievers long to destroy the religion of the Muslims, the verse under discussion says that now they have lost all hope of harming it and their hostile activities against the Muslims have come to an end.
So fear them not and have fear of Me. Allah says: Have fear of Me. What does that mean? Is Allah an enemy of His own religion? No. This verse stipulates the same basic principle regarding Allah's favour that has been mentioned in so many other verses.
One such verse says: "Allah does not change the condition of a people until they change what is in their hearts." (Surah ar-Ra'd, 13:11) Giving the reason for this another verse says: "That is because Allah never withdrawn the grace He has bestowed on any people until they first change that which is in their hearts." (Surah al-Anfal, 8:53) Allah says that He does not withdraw any favour bestowed by Him on a people unless they themselves by their own doings want it to be withdrawn.