وَاَنْزَلْنَآ اِلَيْكَ الْكِتٰبَ بِالْحَقِّ مُصَدِّقًا لِّمَا بَيْنَ يَدَيْهِ مِنَ الْكِتٰبِ وَمُهَيْمِنًا عَلَيْهِ فَاحْكُمْ بَيْنَهُمْ بِمَآ اَنْزَلَ اللّٰهُ وَلَا تَتَّبِعْ اَهْوَاۤءَهُمْ عَمَّا جَاۤءَكَ مِنَ الْحَقِّۗ لِكُلٍّ جَعَلْنَا مِنْكُمْ شِرْعَةً وَّمِنْهَاجًا ۗوَلَوْ شَاۤءَ اللّٰهُ لَجَعَلَكُمْ اُمَّةً وَّاحِدَةً وَّلٰكِنْ لِّيَبْلُوَكُمْ فِيْ مَآ اٰتٰىكُمْ فَاسْتَبِقُوا الْخَيْرٰتِۗ اِلَى اللّٰهِ مَرْجِعُكُمْ جَمِيْعًا فَيُنَبِّئُكُمْ بِمَا كُنْتُمْ فِيْهِ تَخْتَلِفُوْنَۙ ( المائدة: ٤٨ )
Wa anzalnaa ilaikal Kitaaba bilhaqqi musaddiqallimaa baina yadaihi minal Kitaabi wa muhaiminan 'alaihi fahkum bainahum bimaa anzalal laahu wa laa tattabi ahwaaa'ahum 'ammaa jaaa'aka minal haqq; likullin ja'alnaa minkum shir'atanw wa minhaajaa; wa law shaaa'al laahu laja'alakum ummatanw waahidatanw wa laakil liyabluwakum fee maa aataakum fastabiqul khairaat; ilal laahi arji'ukum jamee'an fayunab bi'ukum bimaa kuntum feehi takhtalifoon (al-Māʾidah 5:48)
And We have revealed to you, [O Muhammad], the Book [i.e., the Quran] in truth, confirming that which preceded it of the Scripture and as a criterion over it. So judge between them by what Allah has revealed and do not follow their inclinations away from what has come to you of the truth. To each of you We prescribed a law and a method. Had Allah willed, He would have made you one nation [united in religion], but [He intended] to test you in what He has given you; so race to [all that is] good. To Allah is your return all together, and He will [then] inform you concerning that over which you used to differ. (Al-Ma'idah  : 48)
1 Mufti Taqi Usmani
We have sent down to you the Book with truth, confirming the Book before it, and a protector for it. So, judge between them according to what Allah has sent down, and do not follow their desires against the truth that has come to you. For each of you We have made a law and a method. Had Allah willed, He would have made a single community of people, but (He did not), so that He may test you in what He has given to you. Strive, then, to excel each other in good deeds. To Allah is the return for all of you. Then Allah shall tell you about that in which you disputed.