Even Jesus said Allah. According to an Aramaic dictionary, ( http://www.peshitta.org/lexicon/ ) the word for God in Aramaic (The language which Jesus spoke) is "Aalah", which is the exact same thing as the Arabic "Allah" since in English there are many ways to spell a foreign word (Example you can spell the Muhammad's name in 27 ways, including Muhammad and Mohamed). Jesus said Allah too, so if you consider yourself a serious Christian you should start saying it to follow your god Jesus. Now to see what different prophets called God. Abraham PBUH called him El shaddai Moses PBUH called him Elohim (see Genesis) Jesus PBUH called him Allah Muhammad PBUH called him Allah Two prophets called him Allah, and they are the most known of prophets, Muhammad and Jesus peace be upon them. Nonetheless all of these are Semitic words, so as far as I am concerned, any Semitic word for God is acceptable, but why use a European word for Allah when not a single prophet used a European word? Also, did you notice something? All of these words for Allah begin with either EL or AL, this is because in proto-Semitic (an ancient language which all Semitic languages, such as Arabic and Hebrew, evolved from) the word for God was AL or EL, Abraham PBUH spoke proto-Semitic and he called God "El shaddai", "El" here meaning God and "shaddai" meaning mountain, so basically he called God "God of the mountain". The Semetic languages evolved in a way that they retain the word AL/EL at the beginning of the word, but there is an additional "lah" in Arabic and an additional "lohim" in Hebrew, I hope this clarifies.