Can a person who believes that Jesus is the son of God be a Muslim?
Question

Can you be a muslim and still believe that Jesus is the son of God?
Praise be to Allah.One of the most important principles of belief in Allah is to declare that Allah is above all attributes that imply shortcomings. One of the attributes that imply shortcomings that the Muslim must reject is the notion that Allah has a son, because that implies need and that there is a being who is like unto Him, and these are matters which Allah is far above. Allah says in Soorat al-Ikhlaas, which describes an attribute of the Most Merciful and is regarded as being equal in reward to reciting one-third of the Quran: 
“Say (O Muhammad): He is Allah, (the) One.
Allah-us-Samad [Allah — the Self-Sufficient Master, Whom all creatures need, (He neither eats nor drinks)].
He begets not, nor was He begotten.
And there is none co-equal or comparable unto Him”
[al-Ikhlaas 112:1-4 – interpretation of the meaning]
Because the Christians believe that ‘Eesa (Jesus) is the son of God – exalted be Allah far above what they say – many verses of the Quran deny this claim and refute it, as Allah says (interpretation of the meaning): 
“And the Jews say: ‘Uzair (Ezra) is the son of Allah, and the Christians say: Messiah is the son of Allah. That is their saying with their mouths, resembling the saying of those who disbelieved aforetime. Allah’s Curse be on them, how they are deluded away from the truth!”
[al-Tawbah 9:30]
“O people of the Scripture (Christians)! Do not exceed the limits in your religion, nor say of Allah aught but the truth. The Messiah ‘Eesa (Jesus), son of Maryam (Mary), was (no more than) a Messenger of Allah and His Word, (‘Be!’ — and he was) which He bestowed on Maryam (Mary) and a spirit (Rooh) created by Him; so believe in Allah and His Messengers. Say not: ‘Three (trinity)!’ Cease! (it is) better for you. For Allah is (the only) One Ilaah (God), glory is to Him (Far Exalted is He) above having a son. To Him belongs all that is in the heavens and all that is in the earth. And Allah is All-Sufficient as a Disposer of affairs”
[al-Nisa’ 4:171]
“The Messiah [‘Eesa (Jesus)], son of Maryam (Mary), was no more than a Messenger; many were the Messengers that passed away before him. His mother [Maryam (Mary)] was a Siddeeqah [i.e. she believed in the Words of Allah and His Books]. They both used to eat food (as any other human being, while Allah does not eat). Look how We make the Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) clear to them; yet look how they are deluded away (from the truth)”
[al-Maa’idah 5:75]
 “And the Jews say: ‘Uzair (Ezra) is the son of Allah, and the Christians say: Messiah is the son of Allah. That is their saying with their mouths, resembling the saying of those who disbelieved aforetime. Allah’s Curse be on them, how they are deluded away from the truth!”
[al-Tawbah 9:30]
Because this false belief existed among the Christians, it was essential for those among them who entered Islam to give up these false beliefs which contradict Islam, one of which is this belief. It was narrated that the Prophet (peace and blessings of Allah be upon him) said: “Whoever bears witness that there is no god except Allah alone, with no partner or associate, and that Muhammad is His slave and Messenger and that ‘Eesa is His slave and Messenger, and His Word which He bestowed upon Maryam and a spirit created by Him, and that Paradise is real and Hell is real, Allah will admit him to Paradise (and grant him a position therein) according to his deeds.” (al-Bukhaari, 3435; Muslim, 28). Al-Qurtubi (may Allah have mercy on him) said: From this it may be understood what the Christian must be taught to say when he becomes a Muslim. Fath al-Baari, hadeeth no. 3435.
 Based on this, a person can only be regarded as a Muslim if he disavows himself of this false belief, and believes that Allah is above all shortcomings. Whoever acknowledges the greatness of Allah will find it easy to give up his old beliefs that are not appropriate with regard to Allah. We ask Allah to help us to venerate Him and appreciate how great He is.