فَتَقَطَّعُوا أَمْرَهُم بَيْنَهُمْ زُبُرًا ۖ كُلُّ حِزْبٍ بِمَا لَدَيْهِمْ فَرِحُونَ (53)
(23:53) Yet afterwards people divided themselves into different sects, and each sect rejoices in what it has *48
*48) This is not a mere statement of a fact, but it is a link of the same argument which is being put forward from the very beginning of the Surah. The argument is this: Islam has been the real and original religion of all the Prophets from Noah to Jesus (Allah's peace be upon them all), because all of them brought and taught the same doctrines of Tauhid and the Hereafter. On the contrary, alf the other religions are the perversions of "the real and original religion", which has been tampered with in many ways. Therefore, those who are following the perverted religions are in the wrong and not the Holy Prophet who is inviting them to "the real and original religion".