وَأَنزَلْنَا إِلَيْكَ الْكِتَابَ بِالْحَقِّ مُصَدِّقًا لِّمَا بَيْنَ يَدَيْهِ مِنَ الْكِتَابِ وَمُهَيْمِنًا عَلَيْهِ ۖ فَاحْكُم بَيْنَهُم بِمَا أَنزَلَ اللَّهُ وَلَا تَتَّبِعْ أَهْوَاءَهُمْ عَمَّا جَاءَكَ مِنَ الْحَقِّ

Here ‘the Book’ means the original and basic teachings of religion. This Book of God is a single entity and has been revealed to all the prophets with some changes in respect of language and the order of commandments. However, as regards the outward structure in which the realities of religion are presented, there are differences in the teachings of the various prophets. The reason is not that there are stages in the revelation of the religion which indicate the actual evolution of the religion itself, i.e. it is not that prior to this a less developed or imperfect religion was revealed and thereafter a more developed and entirely perfect religion was revealed. The truth is that with any considerable passage of time, the internal reality of religion is lost and public rituals and formal ceremonies assume the strength of the internal reality, eventually becoming ‘holy’. People begin to consider the repetition of such rituals, accompanied by external trappings, as real worship. That is why the external framework was changed from time to time, so that the mentality of considering this framework as the real substance of religion should be eradicated and so that nothing other than God should become the centre of one’s attention. According to the Quran, this came about simply for the purpose of putting people to the test. The reason for this strategy is the Divine Wisdom of putting mankind on trial and not the Divine Wisdom of the evolution of religion. An example of this is the change of qiblah. The Children of Israel were commanded to turn towards the ‘Holy House’ (Jerusalem) while saying their prayers. This command was only for the sake of being consistent about the direction. But thereafter they gradually developed the idea that prayer meant simply facing towards Jerusalem. Then the earlier commandment was changed and the Ka‘bah was made the qiblah. Now, some people adhered to the earlier tradition, while others followed God’s guidance. In this way, the change of qiblah made it clear as to who worshipped walls and doors and who were the genuine worshippers of God (see 2:143). Now there is no possibility of the occurrence of such a change, because the structure would have to be changed by a prophet and now no other prophet is going to be raised. However, as far as the real purpose is concerned, it is to remain as it is. Even now, before God, His true worshipper will be the one who, though following the structural formalities, will not give them the status of real purpose; who, freeing his mind from outward ceremonial, will say his prayers directly to God. This has to be achieved through rigorous mental discipline. The disputes existing in religion in the name of outward formalities have arisen because people’s negligence has made them ignorant of the true facts. If they were to become aware of the truth — as it will present itself in the Hereafter—all the disputes would come to an end right now.

— Source: Tazkirul Quran (Maulana Wahiduddin Khan) via Quran.com (5:48)