Let’s call God Allah ... ?

Given the amount of times I have to question some Christians about making out that Allah is a fundamentally different deity to the God and Father of our Lord Jesus Christ, I felt, if only for my own future reference, that it would be useful to flag this up:

Christian and Muslim Arabs use the words God and Allah interchangeably. ... the word Allah was already in use by Christians in the pre-Islamic period.

In other words: if one goes around saying Allah is fundamentally different, then you have Christians brothers and sisters in Arabic-influenced lands that are being traduced.
Oh, and the bishop that said this is no pushover when it comes to Islam either:

In the past, Bishop Muskens has offended many Muslims. In 2005 he said Islam was a religion without a future because it had too many violent aspects.

Ref. Dutch Bishop: Let’s call God Allah