For the Muslims, Allah is the name of the One and Only God, Compassionate and Merciful. The Gracious, The Creator, The Sustainer, The Healer, The All-Knowing, The All-Wise, The Lord of the Universe, The First, The Last, and others. He is the Creator of all human beings. He is the God for the Christians, the Jews, the Muslims, the Buddhists, the Hindus, the atheists, and others. Muslims worship God whose name is Allah. They put their trust in Him and they seek His help and His guidance.
    There are traditionally ninety-nine names, or attributes, that Muslims use to describe Allah's nature, 99 names of Allah  The 99 Attributes of Allah 

    Indeed, it is beautiful and impressive the worship of the Muslims to Allah.

    Some non-Muslims mistakenly believe that Allah is an "Arab god," a "moon god," or some sort of idol.  Allah is the proper name of the One True God, in the Arabic language used by Muslims all over the world.  Allah is a name that is neither feminine nor masculine, and it cannot be made plural (unlike god, gods, goddess, etc).  Muslims believe that there is nothing in the heavens nor on earth that deserves worship except Allah, the One True Creator.

    Islam is based on the concept of Tawhid, or Unity of God.  Muslims are strictly monotheistic, and fiercely reject any attempt to make God visible or human. Islam rejects any form of idol worship, even if it is an attempt to get "closer" to God, and rejects the Trinity or any attempt to make God human.

"Say, 'He is Allah, the One;
Allah, the Eternal, Absolute;
He begets not, and neither is He begotten;
And there is nothing that can be compared to Him."
Qur'an 112:1-4

    In Muslim understanding, God is beyond our sight and understanding, yet at the same time "nearer to us than our jugular vein" (Qur'an 50:16). Muslims pray directly to God, with no intermediary, and seek guidance from Him alone, because "...Allah knows well the secrets of your hearts" (Qur'an 5:7).

"When My servants ask thee concerning Me,
I am indeed close (to them).
I respond to the prayer of every suppliant when he calls on Me.
Let them also, with a will, Listen to My call, and believe in Me,
that they may walk in the right way."
Qur'an 2:186

    In the Qur'an, people are asked to look around them for the signs of Allah in the natural world.  The balance of the world, the rhythms of life, are "signs for those who would believe."  The universe is in perfect order:  the orbits of the planets, the cycles of life and death, the seasons of the year, the mountains and the rivers, the mysteries of the human body.  This order and balance are not haphazard nor random.   The world, and everything in it, has been created with a perfect plan, by the One who knows all.

    Islam is a natural faith, a religion of responsibility, purpose, balance, discipline, and simplicity. To be a Muslim is to live your life remembering God and striving to follow His merciful guidance.

Discrepancies between the Koran and the Bible:

    There are some "discrepancies" between the Koran and the Bible, important enough to say that either the Koran is not the word of God or the Bible is not the word of God... they cannot be both "the truth"... one of them is false, even if it has many good things... because God cannot say one single error!.

    For a Muslin, even the suggestion that the Koran may be in error, is a blasphemy... as it happens with a Jew and his Scriptures, and a Christian with the whole Bible... but we should be open-minded... if you were born from Muslim or Jew parents, now, most probably, you would be a Muslim or a Jew, what your parents were!... or a Christian or a Hindu, if your parents were Christians or Hindus...

    And I am not "suggesting" that the Koran has errors... I am saying it!... as follows:

    The "Trinity"... "Mary":

    The Koran proclaims that "the Trinity of the Bible" are three Gods: "The Father, Jesus, and Mary"... as declared in the Sura 5:116, "Then God will say: Jesus son of Mary, did you ever say to mankind: "Worship me and my mother as gods besides God?"...

    ... and this is a "gross error" of the Koran, because the Bible does not say that the Trinity is "the Father, Jesus, and Mary", but "the Father, Jesus Christ, and the Holy Spirit"... and God cannot make that gross mistake!... Jesus and the Bible never ever said that Mary is God, never ever said to worship Mary... only you worship God in the Bible.

    Muslim scholars see the angel Gabriel as the Holy Spirit.

    The "Trinity",

    The Trinity is rejected by the Koran, and in fact it says that to believe in the Trinity is to be an unbeliever, "Unbelievers are those that say: "God is one of three" (5:73)... However, every time God speaks in the Koran he does it as "We", "Us", Our", over 100 times!... showing again and again that God is not a single person, but several persons in one divine being: In Sura 37:70-130 the Koran repeats it at least 17 times: "Noah prayed to Us... We bestowed on him... We gave him... We reword the righteous" and every time writes them with capital, "We", Us", "Our"... "Then We sent forth Moses and Aaron with Our signs" (10:75)... over and over is repeated in the same way in Suras 7:1-11, 2, 6, 10...

    "Jesus Christ":

    There are several important discrepancies between the Koran and the Bible:

    - The Gospels, say that Jesus is God, he was crucified, and he resurrected physically...

    - The Koran, denies the 3 facts... but then, praises the "Gospel of Jesus"... that's a "gross error of the Koran", because if Jesus is not God, and he was not crucified, the Koran should say that the Gospel of Jesus is wrong, instead of praising the Gospel, and advising to follow the doctrines of the Gospel in Suras 5:46 and 5:65... the divinity of Jesus, his crucifixion, and resurrection at the third day, is the "heart of the Gospel"!.

    "God the Father":

    This is not a error but "a missing" in the Koran: Of the 99 attributes of God, is missing "the Father": God is the Creator, the true Father of every Muslim, and every Christian, and Jew, and Hindu... the same Allah who made the hands of a Muslim, made the feet of a Jew, and the kidneys of a Christian... God is the compassionate Father, the merciful as a Father is...

    "Eternally Father":

     This is another "missing" of the Koran...God is eternally the Father of Jesus Christ, eternally begotten, not made, and one in being with the Father; Jesus is eternally God as the Father, because if at any moment God would not have had a Son, at that moment God would not have been a Father, which is an impossible... and Jesus Christ is as much God as the Father, God from God... but not two Gods, only one God!... like the water and ice, not 2 waters, but the same substance in different forms... and the Holy Spirit is like a cloud, also the same water, who proceeds eternally from the love of Father to the Son and the love of the Son to the Father... and there are not 3 Gods, but only one eternal God: The God of Abraham and Ishmael and Isaac, of the Sura 2:133, which are not 3 Gods, but the only one God... and that's why the only one God speaks as "We" and "Us" and "Our", at least 17 times in the Sura 37 of The Ranks, in verses 70-130.

    The "Savior":

    This is another "missing" in the Koran: God loved you so much that he became flesh, Jesus the Christ, to die in a cross to pay for all your bad deeds, so if you believe in Him may not perish, but have eternal life (John 3:16)...

    The certainty of salvation known by the Christian (Jn.3:36, 5:24) is but a vague hope to the Muslim who awaits the Day of Resurrection when "works", not "grace", will determine his destination in the next life: The balance between good and bad deeds determines eternal destiny in Paradise or Hell... God's mercy may tip the balance for a Muslim, but it is arbitrary and uncertain...

    Right now you can have "eternal life": Just believe in the Son, that Jesus Christ is God, and you have "eternal life"... not that you "will have", but that you have it now!, says John 3:36, with a "new life" now on earth, with a little piece of heaven on earth... let us see:

    "God in you":

    This is the great difference of a Muslim, a Jew, and a Christian: For a Muslim and a Jew, God is with him, guiding him to the right path... but for a Christian God is "within him"... "You in me, and I in you", says Jesus in John 15... Christ is inside a Christian, and a Christian is inside Christ, in his Church... because Jesus not only died on a cross to pay for all your sins, but also resurrected to give you a "new life", the life of God in you... and you can have it all right now, just by believing in the Son, in Jesus Christ (John 3:36)... and this is all free, by grace, by the power of the Holy Spirit, your sanctifier, who is with you now, helping you to become a Christian, without forcing you, like a dove, but with the power of God, able to make your life one of service and love... a "new creature" on earth... and, on top of it, a sure eternal Paradise after death.

    "Jews" and "Christians":

    In the Koran, Jews are damned by Allah, and Christians are told that faith in Christ as God incarnate is "blasphemy"... but the same Koran praises and recommends the Torah and the Gospel of Jesus, which is a contradiction.

    "Virgin Mary":

    The Koran says that Jesus was born from a "Virgin", "Mary" (Sura 3:47, 19:20)... and says about Virgin Mary, "God has chosen you. He has made you pure and exalted above womankind... she was a saintly woman" (3:43, 5:75).

    - In 1917, Virgin Mary appeared in "Fatima", Portugal... and in the pilgrimage of her statue to Africa, for the first time Islam trembled, seeing so much devotion to her, with the same name as the wife of Ishmael, and the daughter and heir of Muhammad...

    ... for the second time Islam trembled in Egypt, when a shadow of Mary appeared at the top of a Coptic temple in 1968, and crowds of up to 250,000 were praying together, mostly Muslims with Christians.

    ... And, if you are a Muslim, I want to challenge you: If you have in your life an important but impossible problem with your family, work, or sickness... try Mary of Fatima... pray to her just one Hail Mary every night... and you will see wonders in your life... you don't have to renounce to your religion, nor to believe anything... just pray to her... and I assure you will see wonders in your life!... now!... but I warn you, the boat of Mary only leads to Jesus.   
 

http://islam.about.com/library/weekly/aa052099.htm
http://www.alhikmat.com/islamic_laws.htm
Difficulties in the Qur'an... Contradictions