First of all, there is only One God who created the Universe and all of mankind.
Throughout history, people have created false gods in their minds and come up with false ideas about Almighty God, but regardless of this there is still only One True God - and He alone is worthy of worship. Unfortunately, some non-Muslims have come to incorrectly believe that Muslims worship a different God than Jews and Christians. This might be due to the fact that Muslims sometimes refer to God as "Allah", but also because over the centuries there have been many lies and distortions spread by the enemies of Islam. In actuality, Muslims worship the God of Noah, Abraham, Moses and Jesus --- the same God as Christians and Jews.
The word "Allah" is simply the Arabic word for Almighty God and it is the same word that Arabic speaking Christians and Jews use to refer to God. If you pick up an Arabic translation of the Christian Bible, you will see the word "Allah" where "God" is used in English. But even though Muslims, Jews and Christians believe in the same God, their concepts about Him differ quite a bit. For example, Muslims reject the idea of the Trinity or that God has become "incarnate" in the world. Also, the teachings of Islam do not rely on or appeal to "mystery" or "paradox", they are straightforward and clear.
Islam teaches that God is Merciful, Loving and Compassionate and that He has no need to become man (nor do humans need for Him to). One of the unique aspects of Islam is that it teaches that man can have a personal and fulfilling relationship with Almighty God without compromising the transcendence of God. In Islam there is no ambiguity in Divinity, God is God and man is man. Muslims believe that God is the "Most Merciful", and that he deals directly with human-beings without the need of any intermediary. Actually, the phrase "In the Name of God, the Compassionate, the Merciful" is one of the most repeated verses in the Holy Quran. Additionally, the pure and straightforward teachings of Islam demand that Almighty God be approached directly and without intermediaries. This is because Muslims believe that God is completely in control of everything and that He can bestow His Grace and Mercy on His creatures as He pleases - no Atonement, Incarnation or blood sacrifice is necessary. In summary, Islam calls people to submit to the One True God and to worship Him alone without any partners.