There are many people, among them a multitude of well meaning Christians and Jews, who claim that the Judeo-Christian God and the Islamic Allah are the same. While this affirmation has become politically correct, especially since 9/11, it is spurious and amounts spiritually to blasphemy on the part of Christians and Jews. The definition of Islam (Merriam-Webster Collegiate Dictionary, 11th edition) is: "the religious faith of Muslims [including belief in Allah as the sole deity and in Mohammed as his prophet]" (brackets added). The logical conclusion: God of the Bible and Allah cannot possibly be the same, since Mohammed (also spelled in other similar ways) is nowhere mentioned in holy scripture as a prophet of God, Allah, or anything else.
Also by definition, God and Allah cannot be the same, since the recognition of Allah as "sole deity" rules out the God of Abraham, Isaac, and Jesus (the last prophet as well as the Redeemer, according to Christians). A fundamental of the Ten Commandments is the injunction by God that there will be no other gods placed before him. To believe that God and Allah are the same is to believe that the Holy Bible and the Koran, the only document in which Mohammed and Allah appear, are both inspired of God, instead of just the Judeo-Christian holy scripture, known more familiarly as the Bible. It is obvious that these two documents have entirely opposite positions vis-à-vis the recognition and worship of God. Both cannot be right.
Allah can be considered as an abstract idol similar to a tangible idol like the Baal or the golden calf of the Old Testament, with neither the "prophets of Baal" nor Aaron, the calf's molder, nor Mohammed, the inventor of Islam, more than a voice, signifying nothing except the insistence upon allegiance or adherence to his creation. This is not a disparagement of Islam - each individual has the right/duty to define a personal doctrine or belief-system and worship in her/his own way - but simply a stating of facts. Muslims reject the notion of Christ as Redeemer in the same sense that Christians reject Mohammed as a prophet. Mohammed was probably conversant with at least part of what is known as the Holy Bible and used characters from it to explain his approach to his god, but the notion that God and Allah are/were the same is just that - a notion, whether Mohammed believed that to be the case or not.
Moreover, while Mohammed claimed to receive divine revelation (claimed by Moslems to be from the angel Gabriel), he did not claim divinity itself. Contrariwise, Jesus did claim divinity as his nature, though he lived and was tested in the human arena as all other men exist and are tested. The insistence by Mohammed (A.D. 570?-632), as outlined in the Koran, the collection of his writings and sayings, that Christ was only a prophet places the Koran in conflict with the Bible, in which Christ is designated as the Redeemer of all people, and the son of God [God Incarnate], conceived of the Holy Spirit. This conflict, a vast irreconcilable differentiation, forces the reader to make a determination as to the validity or invalidity of the documents. Either the Bible is the word of God, or the Koran is. Both cannot be, nor can one be an adjunct of the other, so deep is their divergence.
The Trinity - Father, Son, Holy Spirit - is central to the Bible; it does not appear in the Koran, thus forcing the investigator to determine which of the documents is the Word of God. Both cannot be. If either set of "scriptures" is considered untrustworthy with respect to its comparison with the other, it cannot be held as valid. In this case, the doctrine of Trinity, an absolute and non-negotiable element of Christianity (though not of Jewry), demands that the Koran be relegated to nothing more than secular writings. The reverse is true, of course, if the Trinity is not a factor, as is the case with Islam. The individual decides for her/himself.
There doubtless are many more examples with respect to the differences between the Bible and the Koran, and the investigator must take them into consideration when coming to a conclusion regarding which to believe. Again, this is not a disparagement of Islam, but a suggestion that it does not reference the God of the Bible.
This discussion could not end without including affairs of the day. There is no argument with the claim that Islam is inherently peaceful, inveighs against violence, and encourages fellowship among all peoples. There are passages in the Koran, however, that, at least apparently, encourage, if not actually require, violence in the matter of dealing with those who do not adhere to Islam, and these passages are easily found. Space for that will not be taken here. Suffice it to say that the face of Islam being presented to the world's populations today IS one of violence, particularly as applied to governments that are essentially controlled by Islamic religionists such as the ayatollahs in Iran and other places, especially in the Middle East. Almost universally worldwide, violent actions are taken "in the name of" or "at the behest of" Allah, and many of these violent actions are wreaked upon Muslims by other Muslims with whom they disagree, or who just happen to be in the wrong place at the wrong time when a suicide bomber as a religious act does his/her thing. This matter represents an important difference between the ethos of the Bible and that of the Koran.
There is no attempt here to degrade Islam, just something to provoke thought, as well as an attempt to set the record straight with respect to the fact that the Judeo-Christian God and Allah are not one and the same. Hopefully, people will examine this and make up their minds. The matter of belief/worship is an individual thing, and no person should consider him/herself cheapened or insulted by anything written here; no judgment is intended, either. In all camps - Islam, Judaism, Christianity - there are good and bad people. The hope is that the good people will always prevail.