[SeekAndFind]

RE: How do Arabic speaking Christians say ‘God’?

From Wikipedia:

http://en.wikipedia.org/wiki/Allah

Allah is the Arabic word for God (literally ‘the God’, as the initial “Al-” is the definite article).

It is used mainly by Muslims to refer to God in Islam, Arab Christians, and often, albeit not exclusively, by Bahá’ís, Arabic-speakers, Indonesian, Malaysian and Maltese Christians, and Mizrahi Jews.

[reg45]

True, so it make no sense to use the word "Allah" in English when you can use the word "God" instead. It only make sense when you are speaking Arabic.

One further point, "Allah", at least in post-Hijric usage has an implied singularity, meaning "The [One and Only] God", in that there can be only one God.