The Pilgrimage - 22:67 And We have made each community responsible for a set of rules to be followed by them, so let them not dispute with you about it. You call upon your Lord. Surely you are on a straight path.
The division of societies into different groups, such as Jews, Christians, Muslims, etc., is something that Allah has foreseen in order to test people against each other.
The Cow/2:148 Each one of you has a direction and a method he has chosen; so compete in goodness. Wherever you are, Allah will bring you together. Surely Allah is all-powerful.

The Pilgrimage/22:34 We have appointed for each community a distinct form of worship, that they may remember the name of Allah, for He has given them livestock as sustenance. Your God is one God. Submit yourselves to Him alone. Give good news to those who obey.

The Prophets/21:111 I do not know; perhaps it will be a test for you and a means of enjoyment for a certain period.

The Criterion/25:20 All the messengers whom We sent before you used to eat and wander in the bazaars. We made you a test for one another; can you endure? Your Lord is the All-Seeing.

The Table Spread/5:48 We have sent down to you this Book, which confirms the previous Books and replaces them, as a comprehensive truth, so judge between them by what Allah has sent down to you. Do not leave the truth that has come to you and follow their whim. We have appointed for each of you a law and a method, and if Allah had willed, He would have made you all one people. But He tests you with what He has given you. Compete in good deeds. To Allah is the return of all of you. He will inform you of the matters on which you differ.

The Pilgrimage/22:67 And We have made each community responsible for a set of rules to be followed by them, so let them not dispute with you about it. You call upon your Lord. Surely you are on a straight path.

The Table Spread/5:43 How is it that they have the Torah with them, in which is the judgment of Allah, and yet they turn away from it and make you an arbitrator? They do not actually believe.
The Table Spread/5:47 Let the people of the Gospel judge by what Allah has revealed in it. Whoever does not judge by what Allah has revealed, they are the transgressors.

The Cattle/6:53 "We have tested you thus with one another so that they may say, "Are these those whom Allah has chosen and blessed among us?"Does Allah not know better those who respond well!"