The fuqaha and the ‘ulama have clarified that believing in the Prophet (Allah bless him and give him peace) as a bashar is a necessary part of the religion. If anyone, let alone denying him as a bashar, express his ignorance about the matter, he will turn kafir because he did not learn a fundamental belief, as the reliable and authentic books of the Hanafi Fiqh state: “One who says that he does not know whether the Prophet (Allah bless him and give him peace) was a human being or a jinn, he will turn kafir.” (Fusul Imadiyyah, 1350, India; Fatawa Alamgiri, 2:291, Egypt)
This is because acceptance of his bashariyyat is a fundamental belief and this individual is unaware of it.
‘Allamah Muhammad bin ‘Abd al-Baqi al-Zurqani al-Maliki (d. 1122 AH) writes in Sharh al-Mawahib: “If you ask whether having knowledge of his being a bashar and an Arab is a precondition for belief (iman) to be valid or it is fardh kifayah (obligation if performed by some will be considered for all) on parents, for example, if one teaches it to his mature son, his other partner will not be questioned about.
Shaykh Wali al-Din Ahmad bin ‘Abd al-Rahim al-Iraqi al-Hafiz ibn al-Hafiz replied that it is precondition for iman to be valid. So, if a person says: I believe in Muhammad (Allah bless him and give him peace) as Messenger to all creation, but I do not know whether he is from amongst the bashar or angels or jinn, or he says: I do not know whether he is an Arab or ‘Ajam (non-Arab), he will undoubtedly become a kafir as he rejects the Qur’an where Allah says: ‘He is the One who raised amidst the unlettered people a messenger from among themselves.’ (62:2) and ‘nor do I say to you that I am an angel’ 96:50). Such a person also belies what was received by the Muslims generation to generation and it is known fully to all the classes and masses. According to me, there is no difference of opinion in this matter. (Sharh Mawahib, 2:68, Egypt)
وقد سئل الشيخ ولي الدين العراقي هل العلم بكونه صلى الله عليه وسلم بشراً ومن العرب شرط في صحة الإيمان أو من فروض الكفاية؟ فأجاب بأنه شرط في صحة الإيمان، ثم قال: فلو قال شخص: أومن برسالة محمد صلى الله عليه وسلم إلى جميع الخلق لكن لا أدري هل هو من البشر أو من الملائكة أو من الجن، أو لا أدري هل هو من العرب أو العجم؟ فلا شك في كفره لتكذيبه القرآن وجحده ما تلقته قرون الإسلام خلفاً عن سلف وصار معلوماً بالضرورة عند الخاص والعام ـ ولا أعلم في ذلك خلافاً ـ فلو كان غبياً لا يعرف ذلك وجب تعليمه إياه فإن جحده بعد ذلك حكمنا بكفره انتهى
‘Allamah Sayyid Mahmud al-Alusi al-Hanafi (d. 1270 AH) writes: “Shaykh Wali al-Din al-Iraqi was asked whether having knowledge of the Prophet (Allah bless him and give him peace) being bashar and an Arab is a condition for iman to be valid or is it fardh kifayah? So, he replied that it is necessary for iman to be valid. He further said: if a person says: I believe in Muhammad (Allah bless him and give him peace) as Messenger to all the creation, but I do not know whether he is from amongst the bashar or angels or jinn, or he says: I do not know whether he is an Arab or Ajam, then there will no de doubt in his kufr as he rejects the Qur’an and denies what was received by the Muslims generation after generation and was essentially known to all the classes and masses. According to me, there is no difference of opinion in this matter. If someone is ignorant and unaware of it, he should be informed of it, and if he denies it afterwards, we will declare him kafir.” (Tafsir Ruh al-Ma’ani, under vers 3:164, 4:101, Egypt)
(Taken from: Nur wa Bashar, ‘Allamah Sarfaraz Khan Safdar)