- Outside Indonesia you hear things like "Indonesia is the largest Muslim nation" and the idea of joining with Malaysia to form a large Muslim Caliphate. So it was a surprise to arrive and find there are 40 million Christians and large areas of Sumatra are almost 100% Christian. And then I realised that the whole way of counting Muslims is open to question. One of the reasons for the name "Dark Ages" in Europe is that hundred years ago there was no freedom of religion; Authorities would twist the law to say that having a different religion was blasphemous and punishable by death. But actually today it’s that way in many countries. Usually people have their religion printed on their I’D card. Incredibly although the Koran prescribes no punishment for changing religion Mohammed is supposed to have said "Whosoever changes his religion, Kill Him" Sahih Bukhari 9:84:57
Incredibly this is largely accepted as valid, so unlike people in the rest of the world you are not free to choose your religion. (But some scholars say Mohammed meant at that particular time not in general forever.)
Of course this is outrageous and against human rights laws and principles. So counting the number of Muslims in a country isn't a valid measurement. But the politicians are able to exploit this.
Wikipedia says -highly controversial cos
1 Quran itself is silent on the punishment for apostasy
2 The hadith (the body of quotes attributed to Muhammad) "Whosoever changes his religion, Kill Him" Sahih Bukhari 9:84:57
Is accepted as valid, but some scholars say he meant at that particular time not in general forever.
3. It contradicts the UN International Covenant on Civil and Political Rights, which says people have the right to choose religion.
4. Islam Online, a hugely popular Muslim website, contains a fatwa dated 21 March 2004 'IOL Shariah" Caliph should kill the apostate
5. This death sentence is carried out in 6 or so extreme countries, but not indonesia.