The word "Allah" is the perfect description of the "One God" of monotheism for Jews, Christians and Muslims!
Is "Allah" only for Islam and Muslims?
[No! It is for All Three Abrahamic Faiths.]
"Allah" is the same word used by Christian Arabs and Jewish Arabs in their Bible, centuries before Islam came.
On page one… (more) [1] of Genesis in the Old Testament, we find the word "Allah" seventeen [17] times.
Every hotel and motel has a Bible. Next time you see one look in the introduction, you will find samples of the different languages they have translated. For Arabic they have translated the verse in the New Testament in Arabic from the famous verse in the Gospel John 3:16 -
"For God so loved the world..."
- and the word the translators used in Arabic for "God" is the very same word used by Muslims around the planet, "Allah." Where Does the word "Allah" Come From?
"Allah" comes from the Arabic word "elah"a god' or something worshiped. - (Arabic) means '
This word (elah) can be made plural (gods), as in "aleha" and it can be male or female just as the word in English can be "goddess."
"Allah" comes from "elaha" but it brings more clarification and understanding.
Allah = Has no gender (not male and not female)
"He" is used only out of respect and dignity - not for gender
Allah = Always singular - Never plural
"We" is used only as the "Royal WE" just as in English for royalty
Allah = Means "The Only One to be Worshipped"

Tawheed (montheism) The term is derived from the three consonants root w-h-d, which serves as the vehicle for the basic concept of oneness,or unity, along with the closely related ideas of singularity and uniqueness. These root letters are clearly apparent in the numerical adjective wahid [one]. In the words of the Qur`an: Your God is surely One. (37:4) inna Ilaaha-kum-la-Wahid The term Tawheed demands a lengthier translation, namely: “the realization-and-affirmation-of-Oneness. The Unity of God, the Divine Unity, Unity in its most profound sense. Allah is The Real, The Absolute. Allah is One in His Essence, His Attributes and His Acts. Before the existence of the universe there was nothing but The Creator. The Qur`an declares that Nothing is like Him (42:11). Allah is omniscient and all-powerful. All of Allah’s attributes belong to Him exclusively. He is the first and there is no last but His oneness. He is the First without anything before Him. He is the Last without anything after Him. The end is with Him alone, and He is the End. He is All-Existing: with him there is no end. Allah is now as He was before. He is Eternal. Tawheed can be viewed from the perspectives of: Tawheed al-Rububiyah Unity of Lordship Tawheed al- Uluhiyah Unity of Worship Tawheed al- Asma wa Sifaat Unity of His Names and His Attributes Tawheed al Itabaa Unity in the following the Prophet Muhammad, peace be upon him Tawheed undoubtedly is the central theme and message of the Qur`an, the Book of Allah and it is repeated in many other verses. The Arabs in Mecca and later the Jews in Medina inquired from Allah’s Rasul (SAW), who is Allah? Allah revealed in Surah Ikhlas (S: 112) as follows: In the name Of Allah, The most Gracious, The Most Merciful. Say, Allah is One, Allah The Everlasting, The Eternal, He has not given birth and was not born, And no one is comparable to Him In another verse, Surah (chapter) 24:35, an image of spiritual discernment of Allah is mentioned, Allah is the Light of the heavens and the earth.. Light upon Light! And Allah guides to His Light whom He will. These verses confirm the Unitary belief, which is the mainspring of Islam and the core of The Qur`an. Further, only in total acquiescence in Allah's good pleasure, renunciation of one’s own will, and surrender to His will and guidance is Tawheed made perfect. Allah's absolute unity is the beginning and the end of the spiritual life for Muslims. The Unity of Allah is a magnificent and a beautiful concept, and Muslims reaffirm their adherence to it many times a day. To acknowledge the fact of the “affirmation-of-Oneness” renew your faith by frequent invocation of La ilaha illa llah [there is non worthy of worship accept Allah] will be the means to eradicate Shirk [polytheism]. It is a powerful and effective concept for focusing and organising one's worldview and epitomising a religious and psychological orientation and authentically expressive of an important facet of the spirit of Islam. Shirk Polytheism The opposite of Tawhid is expressed by the Arabic term Shirk (polytheism), derived from the root Sh-r-k which conveys the notion of sharing or partnerships. The word Sharik (plural shurakaa) means partner or “associate. It encompasses far more than the more blatant forms of idolatry and denial of Allah's Unity. The term Shirk means associating partners with Allah, and the related term mushrik is applied to someone guilty of such polytheistic association. Forms of Shirk: Major Shirk Includes Shirk ad Duâ invoking or supplicating to a false deity besides Allah Shirk al-Niyah wa Iraada wal Qasd having the intention and determination to deliberately worship a deity other then Allah. Shirk at- Ta obeying any created being against the command of Allah. Shirk al-Muhabbah loving a created being or an object more than Allah Hidden Shirk as:Shirk al- khafi means the hidden, or covert, association of partners with Allah, the One and Only God. This is an insidious form of Shirk. Minor forms of Shirk as: Shirk ar- rea carrying out religious acts for worldly gain, e.g. showing off.Shirk at- Tasmee swearing by other then Allah.Allah says in the Noble Qur`an that Shirk is the greatest sin. (S 31: 14)He also says that He will forgive all other sins if He wishes, except Shirk (S 4: 49)Muslims must understand the term Shirk (polytheism) and be conceptually and practically clear that it is diametrically opposed to, Tawheed, the affirmation to the Oneness of Allah.
How Does One Become a Muslim?

In order to become a Muslim, there are no specific religious rituals or customs that you need to perform, neither in specific areas nor in front of people. This is because in Islam a person has a direct relationship with his Lord without any intermediaries. By simply believing and declaring that there is only one God and that Muhammad is His slave and Messenger one thereby becomes Muslim. Upon making this statement sincerely every sin in his/her life up to that point is forgiven. God says in the Holy Qur’an ?Except those who repent and believe and do righteous deeds; for those, God will change their sins into good deeds, and God is Ever Oft-Forgiving, Most Merciful ? (25:70) You begin life again as a Muslim, one who submits to the will of God. As for non-Muslims who have accepted Islam, they will be given their reward in double, due to their belief in their messengers as well as their belief in Muhammad. Allah says: ((Those to whom We gave the Scripture [Torah and the Gospel, etc.] before it, - they believe in it (the Qur’an). * And when it is recited to them, they say: We believe in it. Verily, it is the truth from our Rubb. Indeed even before it we have been from those who submit themselves to Allah in Islam as Muslims. * These will be given their reward twice over, because they are patient, and repel evil with good, and spend (in charity) out of what We have provided them )) (28:52-54) In addition to this, Allah effaces all the sins they did before accepting Islam. The Prophet said: “Islam effaces all [the sins one did] before it?” (Muslim).

The Oneness of God

The Qur'an reminds us of the falsity of all alleged gods. To the worshippers of man-made objects it asks:

Do you worship what you have carved yourself? (37:95) Or have you taken unto yourself others beside Him to be your protectors, even such as have no power either for good or for harm to themselves? (13:16)

To the worshippers of heavenly bodies it cites the story of Abraham: When night outspread over him, he saw a star and said, "This is my Lord." But when it set, he said, "I love not the setters." When he saw the moon rising, he said, "This is my Lord." But when it set, he said, "If my Lord does not guide me, I shall surely be of the people gone astray." When he saw the sun rising, he said, "This is my Lord; this is greater." But when it set, he said, "O my people, surely I quit that which you associate, I have turned my face to Him who originated the heavens and the earth; a man of pure faith, I am not one of the idolaters." (6:76-79)