Although the name "Allah" is most commonly associated with Islam, it was also used in pre-Islamic times. It was used by Arab Christians in the pre-Islamic Umm al-Jimal inscription (6th century). The father of Muhammad, Islam's prophet, had the name "Abdullah", which translates "servant of Allah". The Hebrew word for deity, El (אל) or Eloh (אלוה), was used as an Old Testament synonym for Yahweh (יהוה). The Aramaic word for God is alôh-ô (Syriac dialect), which comes from the same Proto-Semitic word (*ʾilâh-) as the Arabic and Hebrew terms; Jesus is described in Mark 15:34 and Matthew 27:46 as having used this word on the cross (in the forms elô-i and êl-i respectively). One of the earliest surviving translations of the word into a foreign language is in a Greek translation of the Shahada, from 86-96 AH (705-715 AD), which translates it as ho theos monos[1] (
http://www.islamic-awareness.org/Histor ... enlp1.html), literally "the one god".
http://en.wikipedia.org/wiki/Allah