IN THE DAYS of Abraham, the religions of the Near East, India and China had hundreds of gods, and hundreds of names for their gods. Thus, The Encyclopedia of Gods by Michael Jordan contains over 2.500 entries of individual deities from ancient and modern cultures and societies.
Jordan also includes several entries of spiritual teachers and miracle working humans who lived and died among their fellow humans, and were then in retrospect elevated into deities like: Asklepios. Confucius, Siddhartha Gautama and Tin-Hau. Who was Tin-Hau?
She a young woman who for more than a dozen years had many dream visions of sinking fishing ships that she was able to rescue. Not long after her death at age 28, her story was inscribed on the walls of a sanctuary in Hangchiow, China (in 1228); and she was deified 50 years later by the Mongol emperor Kublai Kahn. So she became a goddess.
But for those religions that trace their prophets back to Prophet Abraham, and his two sons Ishmael and Isaac, the many names of God simply describe different aspects or attributes of the one God’s multifaceted personality.
God’s names are appellations: titles and descriptions. Thus to say that God is a King or Judge describes one of many ways God acts. To say that God is the Compassionate One is to describe one of many character or personality traits of the one God.
While each of the many ‘names’ for the one God is only one of the many appellations of the one universal creator of space and time; both Islam and Judaism also have one special Divine name that is always in the believer’s heart and soul.
Because the Qur’an is filled with beautiful Arabic poetry, it is not surprising that the Qur’an is also filled with so many names of God.
Because the Jewish tradition reaches back more than thirty five centuries; it is not surprising that Jews have focused on many additional names for the one and only God over those many centuries.
Yet, because all the many names of God call upon the same One God, it is also not surprising that many of the 99 beautiful names of God in Muslim tradition also appear in Jewish tradition, which sometimes refers to the 70 names of God (found in Midrash Shir HaShirim and Midrash Otiot Rabbi Akiba).
Since Arabic and Hebrew are brother languages; in some cases the names even sound alike:
Arabic Hebrew English
Al-Raḥman Ha Rakhaman the Compassionate One
Al-Raḥim El Rakhum the Merciful One
Al-Quddus Ha Kadosh the Holy One
Al-Bari Ha Boray the Creator
Al-ʿAliyy El Elyon the Most High
Al-Salam Oseh HaShalom the Peacemaker
Malik Al Mulk Melek Malkay Melakim the King/Ruler over all the kingdom/ kings
Al-Muhyi Ha Michayah the Giver of Life
Al-Mumit Ha Maymeet the Taker of Life
Most of the similarities between Jewish and Muslim appellations of God are not due to linguistics alone. They reflect similar philosophical views of God’s attributes.
However, since for more than twelve centuries, the only ongoing monotheistic religious community in the world existed within Israel, the Jewish People, where the universal attributes of the one and only God were frequently expressed in the Hebrew Bible in terms of His activity and relationship to Israel.
For example, Elohei kol basar, the God of all flesh (Jeremiah 32:27) is usually referred to as Elohei Yisrael or Elohei of Abraham, Isaac, and Jacob (Exodus 3:15). Thus, Prophet Isaiah refers to both The Holy One (Isaiah 40:25) and The Holy One of Israel (Isaiah 1:4, 5:19) and Prophet David refers to both El Yisrael The God of Israel (Psalm 68:36) and El HaShamayim The God of the Heavens (Psalm 136:26).
Of course, just as one parent can love, protect, and judge many children, the One God of Israel is also the one God of the whole world, So Ezra, the most narrowly focused of prophets, uses both Elah Yisrael, God of Israel (Ezra 5:1) and Elah Sh’maya V’Arah, God of Heaven and Earth (Ezra 5:11).
The words El, Elah, Elohei and Elohim are all pre-Abrahamic West Semitic generic terms for a God or for the many gods. In these various forms they appear almost 3,000 times in the Hebrew Bible. But the verb that describes the Divine action is singular, not plural.
In the same way, God is described with male metaphors but these are not to be taken literally, just as the pronoun “we” in the Quran never means that the Divine One has any associates.
In both the Holy Quran and the Holy Bible, the same soul nefesh in Hebrew and nafs in Arabic is ascribed to both men and women even though in both Hebrew and Arabic the word is grammatically feminine.
In polytheistic systems of religion there really are both ‘male’ gods and ‘female’ goddesses. Ilâh (“god,” or “goddess”) is a feminine noun in Arabic grammar, in contrast to the male noun Allâh which is replaced with a masculine pronoun, huwa, “He.” The Quran freely refers to Allah using the Arabic pronoun, huwa (“he”), never hiya (“she”) just as is done in the Hebrew Bible. In pre-Islamic society, hiya would have been appropriate to refer to any of the pagan goddesses like Al-Lât, Al-Uzza and Manât, whom people thought of as ‘daughters’ of Allah.
Since Islam and Judaism are very close yet uniquely different religions, there are also several Jewish names for God’s attributes that are not found among the 99 names that appear in the Quran. 
For Jews the most important name of the one God, the name that God himself revealed to Moses at the burning bush, is YHVH: which appears more than 6,800 times in the Hebrew Bible.
In Exodus 3:13-15, Moses said to God, “If I go to the Israelites and tell them, ‘The God of your fathers has sent me to you,’ and they ask me, ‘What is his name?’—what should I say to them?” And God said to Moses, “Ehyeh asher Ehyeh.”
Ehyeh is the verb ‘to be’ in its future tense singular form and means ‘I will/might/may become the one Who I may/will/might become,’ indicating that Ehyeh is The God of Potentialities, The God of Possibilities, The Living God of Becoming and Transforming, the One who can liberate Israel from bondage in Egypt.
Unfortunately, the Greek and Latin translations of this verse were influenced by the Greek philosophical idea that God was similar to a permanent ideal form (like an equilateral triangle) or an ‘unmoved mover,’ and that God is not like a living personality.
Since they thought God must be a static unchanging being., they mistranslated “Ehyeh asher Ehyeh’ as ‘I am who I am’ rather than its plain meaning of ‘I can be whatever I will be [to redeem you]” i.e. God Almighty.
The Torah continues, “And God said, ‘You must say this to the Israelites, “I Am” (the usual mistranslation for God’s self-revealed name) has sent me to you.’” God also said to Moses, “You must say this to the Israelites: Ehyeh, the God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob—has sent me to you. This is my name forever, and this is my memorial from generation to generation’ (Exodus 3:13-15).
When Jews speak of God in the third person, God’s name is YHVH– “the One who causes being and becoming, the One who brings potentials into existence.”
This name was spoken publicly from the time of Moses and throughout the centuries of the 1st Temple of Solomon, but it was replaced by Adonai (Lord) before the beginning of the 3rd c. B.C.E., because God’s actual holy name was eventually considered too holy to utter audibly.
In later centuries even the substitution was considered too holy to utter; and the custom among pious Jews till this day is not to use any name for God at all (except in prayer); but to say HaShem–the name (of God) when speaking about God.
The distinction between the personal intimate name of God that the believer uses in prayer and when reciting his or her holy scripture versus all other names, is a measure of the believer’s piety and love of the God of his or her own religion.
Some Muslims say that ‘Allah’ is the Arabic word for God and so the word ‘Allah’ can be used by non-Muslims to refer to their own religious concept of God. Other Muslims vehemently oppose this. They maintain that no believing Muslim should translate the English sentence ‘Zeus is a Greek God.’ as ‘Zeus is a Greek Allah.’ It is absurd, they say, sacrilegious and an affront to Islam. Allah is the name of the one and only God and not just a word for a generic divinity.
When Christian believers speak about Jesus, they are referring to the “Divine Son of God” who connects them to God the Father. When Jews or Muslims speak about Jesus they are referring not to God, but only to a man of God.
By refusing in principle to utter the sacred name represented by the sequence of letters ‘YHVH’ and by uttering instead ‘HaShem,’ Jews mean to properly honor the God who made a covenant at Mount Sinai with the descendants of their ancestors Abraham, Isaac and Jacob/Israel. Neither Christians or Muslims connect to God this way.
When Muslims use the word ‘Allah’ they mean the one God they worship and adore, the one Who sent at least one prophet, speaking his own language, to every nation and tribe in the world, and Who sent Prophet Muhammad to proclaim the Quran in Arabic. This is the same one God who sent Jesus to proclaim the Gospel and Moses to proclaim the Torah. Neither Jews nor Christians connect to God in this very universal way.
Thus, for Muslims the word ‘Allah’ is both a generic for the one God of all monotheistic religions and at the same time a special personal Islamic name when spoken with devotion and love by a Muslim.
As a neutral outsider, and an American Reform Rabbi, I can understand why many Muslims would object to Christians using the word Allah in the context of saying that Jesus is the son of Allah. Another word for a generic divinity is needed. On the other hand, a Muslim would say that Allah spoke to Jesus as the Quran itself states, “Allah said: Jesus, I will take you back and raise you up to Myself…” (3:55)
If people of good will use the generic aspect of the word Allah only in a monotheistic context, and use another word for a trinitarian or polytheistic context, we might have more light and less heat in our own religious lives.