How does religion define a nation?

COULD somebody please clarify the following issue in my mind?

If you are a South African Jew or a South African Muslim, are you a South African, or a Jew or a Muslim first and foremost?

If Jews are the followers/ practitioners of Judaism, and Muslims that of Islam, how can any country base their nationality on a certain religion when there are many other indigenous people in that country with their own religion, cultures and traditions. (SA is a great example).

I believe a country can only say it is called after a certain religion when 100% of the people practise that religion. Thus, can the Jews or any country call itself Jewish, Islamic or Buddhist if not 100% as stated above?

The promotion of such practises in the Middle East and some parts of the rest of the world can only be done via discrimination, oppression, religious intolerance and apartheid practices against the minority indigenous peoples of that part of the world.

Leaving all the Arab and “Islamic” countries aside for a moment, the question to Israel is: When you have Jews from all nationalities coming to Palestine in droves, can you say that these Jews with their different nationalities are more entitled to enjoy the Land of Palestine above the indigenous people of the land (which include Palestinian Jews)?

So now you deny and exclude the original inhabitants of Palestine their birthrights, and by force and the help of others you declare Palestine to become Israel 70 years ago based on religion, even stolen by violence (with the help of God) 3 000 years ago.