God is not Jesus, and Jesus is not God.2 Even Jesus himself rejected this. God has said in the Quran:
Indeed, they have disbelieved who have said, “God is the Messiah (Jesus), son of Mary.” The Messiah said, “Children of Israel, worship God, my Lord and your Lord. Whoever associates partners in worship with God, then God has forbidden Paradise for him, and his home is the Fire (Hell). For the wrongdoers,3 there will be no helpers.” (Quran, 5:72)
God is not a trinity. God has said in the Quran:
Indeed, they disbelieve who say, “God is the third of three (in a trinity),” when there is no god but one God. If they desist not from what they say, truly, a painful punishment will befall the disbelievers among them. Would they not rather repent to God and ask His forgiveness? For God is Oft-Forgiving, Most Merciful. The Messiah (Jesus), son of Mary, was no more than a messenger... (Quran, 5:73-75)
Islam rejects that God rested on the seventh day of the creation, that He wrestled with one of His angels, that He is an envious plotter against mankind, or that He is incarnate in any human being. Islam also rejects the attribution of any human form to God. All of these are considered blasphemous. God is the Exalted. He is far removed from every imperfection. He never becomes weary. He does not become drowsy nor does he sleep.
The Arabic word Allah means God (the one and only true God who created the whole universe). This wordAllah is a name for God, which is used by Arabic speakers, both Arab Muslims and Arab Christians. This word cannot be used to designate anything other than the one true God. The Arabic word Allah occurs in the Quran about 2700 times. In Aramaic, a language related closely to Arabic and the language that Jesus habitually spoke,4 God is also referred to as Allah.
2) Belief in the Angels:
Muslims believe in the existence of the angels and that they are honored creatures. The angels worship God alone, obey Him, and act only by His command. Among the angels is Gabriel, who brought down the Quran to Muhammad .
3) Belief in God’s Revealed Books:
Muslims believe that God revealed books to His messengers as proof for mankind and as guidance for them. Among these books is the Quran, which God revealed to the Prophet Muhammad . God has guaranteed the Quran’s protection from any corruption or distortion. God has said:
Indeed, We have sent down the Quran, and surely We will guard it (from corruption). (Quran, 15:9)
4) Belief in the Prophets and Messengers of God:
Muslims believe in the prophets and messengers of God, starting with Adam, including Noah, Abraham, Ishmael, Isaac, Jacob, Moses, and Jesus (peace be upon them). But God’s final message to man, a reconfirmation of the eternal message, was revealed to the Prophet Muhammad . Muslims believe that Muhammad is the last prophet sent by God, as God has said:
Muhammad is not the father of any one of your men, but he is the Messenger of God and the last of the prophets... (Quran, 33:40)
Muslims believe that all the prophets and messengers were created human beings who had none of the divine qualities of God.
5) Belief in the Day of Judgment:
Muslims believe in the Day of Judgment (the Day of Resurrection) when all people will be resurrected for God’s judgment according to their beliefs and deeds.
6) Belief in Al-Qadar:
Muslims believe in Al-Qadar, which is Divine Predestination, but this belief in Divine Predestination does not mean that human beings do not have freewill. Rather, Muslims believe that God has given human beings freewill. This means that they can choose right or wrong and that they are responsible for their choices.
The belief in Divine Predestination includes belief in four things: 1) God knows everything. He knows what has happened and what will happen. 2) God has recorded all that has happened and all that will happen. 3) Whatever God wills to happen happens, and whatever He wills not to happen does not happen. 4) God is the Creator of everything.
From Islamreligion.com