If a person believes in God and that Muhammad (Sallallahu Alaihi wa Sallam) is His Prophet, but this person does not believe that some orders which are written in the Qur'an came from Allah, can he be considered Muslim?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Among the six pillars of belief is believing in the Books Sent down by Allah through His Messengers such as al- Torah, al-Injeel, al-Zaboor and the last Book is the Qur'an that was revealed to the Prophet (Sallallahu Alaihi wa Sallam) as a bearer of glad tidings and a Warner. No one will be a Muslim unless he believes in the whole Qur'an. Allah Says (interpretation of meaning): {And who believe in (the Qur'ân and the Sunnah) which has been sent down (revealed) to you (Muhammad ) and in [the Taurât (Torah) and the Injeel (Gospel), etc.] which were sent down before you and they believe with certainty in the Hereafter. (Resurrection, recompense of their good and bad deeds, Paradise and Hell, etc.). They are on (true) guidance from their Lord, and they are the successful.} [2: 4-5].
Allah informed us about the people of the Book who believe in the Prophet (Sallallahu Alaihi wa Sallam) and his Book in this verse: {And when it is recited to them, they say: "We believe in it. Verily, it is the truth from our Lord. Indeed even before it we have been from those who submit themselves to Allâh in Islâm as Muslims (like 'Abdullâh bin Salâm and Salmân Al-Farisî, etc.).} [28: 53].
Allah has declared that believing in a part of the Qur'an and disbelieving in the other parts has no benefit, as He said disapproving the practice of Jews: {… Then do you believe in a part of the Scripture and reject the rest? Then what is the recompense of those who do so among you, except disgrace in the life of this world, and on the Day of Resurrection they shall be consigned to the most grievous torment. And Allâh is not unaware of what you do.} [2: 85].
It is narrated in the known Hadith of Jibraeel that he asked the Prophet (Sallallahu Alaihi wa Sallam) about belief and he replied: "Faith is to believe in Allah, His Angels, (the) meeting with him, His Messengers, and to believe in Resurrection" [Reported by Imam Muslim ].
Allah Says (interpretation of meaning): {The Messenger (Muhammad SAW) believes in what has been sent down to him from his Lord, and (so do) the believers. Each one believes in Allâh, His Angels, His Books, and His Messengers. They say, "We make no distinction between one another of His Messengers" …} [2: 285].
All the Muslim Ummah has agreed that anyone who denies something that is mentioned in the Qur'an whether it is its commands or reports, or if he approves of something that is disapproved of in the Qur'an, or disapproves of what is approved of in the Qur'an after having knowledge of it, is a Kafir even if he denies only a letter of the commonly known alphabet of the Qur'an.
Allah knows best.