I refer to Setatanta O'Hailpin's letter Tuhan more appropriate translation for 'God'. He stated that Christian Arabs prefer to use the Arabic version of Jesus, 'Isa'.
Firstly, as a Christian, I can tell you that 'God' and 'Jesus', while related concepts, are not exactly the same thing in Christianity. Both words are used in the Bible, and it would be inappropriate to translate every occurrence of the word 'God' in the original Greek as 'Jesus'. The Greek words for 'God' and 'Jesus' are different.
All Arab Christians I have ever known refer to God as 'Allah'. Therefore, it would make complete sense to translate 'God' in the Indonesian Bible as 'Allah' as Bahasa Indonesia, just like Bahasa Malaysia, has many Arabic borrowed words. 'Allah' is one of them.
This is also consistent with Islam. Time and time again, my Muslim friends assert to me that we Christians worship the same God as they do. This is especially true of Muslims who are serious about their religion who try to persuade me to become a Muslim.
In fact, I have travelled to and lived in many other countries, and it is only in Malaysia (and perhaps Singapore) where the question even arises. No non-Malay Muslim I have ever met has ever denied that Allah is the same God that Jews, Christians and Muslims all worship.
In fact, the only non-Malaysians I have ever met who claim that the Christian God is not the same as Allah are anti-Muslim extremist fundamentalist Christians in the US!
So, in my personal experience, there are only two groups of people who deny that Christians, Jews, and Muslims all worship the same God, who is known in Arabic as Allah, They are certain Malay Muslims in Malaysia and certain anti-Muslim fundamentalist Christians in the US.