Allah is in the Bible?!?
YES!!

Then why do Jews, Christians and Messianics not believe in Allah??
Very good question; as with All Religions, formal, institutional Religion is only in the business of propagating itself. Religion becomes “hardened” and opposed to change when something doesn’t line up with what is taught to them by their religious authorities. In this case, it is the Jewish part of the Bible, the Tenakh, where you find “Allah” referred to. To make it even more ironic, the Elohim(God), “Allah”, was referred to NOT by some Muslim nabi but a Jewish nabi, about a thousand years before Mohammad!! Impossible you say?? Well let me show you today where you can find the name of your Elohim (God) in the Judaeo-Christian Bible. You will see that the Aramaic name written for all Time is spelled EXACTLY as it does in Arabic!
MEET DANIEL THE JEWISH NABI
Because Daniel is not a Nabi in the Muslim community, it would be good for everyone to know some of the background of this Daniel and why he would be important to the Muslims because it would show that Muhammad wasn’t the first to reveal Allah to an unbelieving world!
Daniel’s significance came into being approximately 1222 years B.H. (give or take 5 years according to most scholars). The Jews say that he lived to 95 but his story begins when he was a teenager, when he was taken into captivity by a pagan-worshiping king named Nevuchadnetzar.
Like their pagan-worshiping Israelite brethren who were destroyed 125 years earlier, the Jews were sliding into immorality and this was their first Judgment against them.
Like a Muslim youth, Daniel was Faithful to the God of Heaven. He was taught to believe in Yehuah (Y-H-V-H) but Daniel told this Warrior-king to worship Him by a different name that he would reveal. Like a faithful Muslim, Daniel refused the unclean meat and wine that his Captors fed to him and his friends. Like a faithful Muslim, Daniel’s Jewish friends refused to bow down to Idols – and that’s when the pagan Nevuchadnetzar was going to punish them and make them an example to all his citizens who refused to bow down to his idol. He threw them into a Fire and the Book of Daniel says that an Angel saved his friends from a certain death (Daniel was not punished because he was a Nabi). When the king saw that the fire had no effect on them, he issued a decree to his entire kingdom, from modern Kuwait to Lebanon, that no one would blaspheme their Elohim.
Which God did Daniel tell the ancient King of Bavel?
By this time, Daniel had become a prophet/nabi to Nevuchadnetzar because he could interpret dreams that the king had. Listen to what Daniel says to the most powerful king in that generation in chapter/surah 4:21

(Northern and central) Middle East while the Babylonian Empire ruled. This means that when the Babylonian Empire died out, the name of Allah continued to circulate throughout the Middle East because he was established as one of the gods. More empires arose and fell and when you fast forward 900 years later when Muhammad was raised up, he told the Meccan and Medinian people:
“There is no God but Allah…”
Why did he declare this?? Think about it!… You have a people entrenched in paganism, they worship multiple gods and if it was revealed that the truth is that there is only ONE El(God), which one would you declare?? You had the sun-god, the earth-god, the fertility-god, the rain-god, etc. and even though all these may be powerful, if you had one who is known as “the Supreme God”, would it not make sense that that one is above ALL the pantheon of gods?? I do not mock the revelation given to Muhammad here but merely to say that it didn’t take divine revelation to know which Elohim (God) was THE one, true God! Jibril’s revelation only reinforced the reality in Muhammad’s day.
But there is an irony in all of this: The angel Jibril, who spoke to Muhammad, is the self-same Gabriel spoken of in the Bible! Gabriel is not only a Messenger to the Arabic people but also to the Hebrew people. If the Arabic people knew this small fact, it should make one wonder, “why did this angel speak to Muhammad hundreds of years later after he sent messages to the Israeli-Jewish people??” The answer is earth-shattering and has been a mystery until now but rather than writing another 10 pages, I will invite you to read the longer, printed version of this pamphlet on this website, (especially the reconciliation of Allah’s name in Aramaic with Arabic)