Non-Ahmadi Muslim scholars say that Jesus(as) shall descend in latter days not as a Prophet but as a mere follower of the Holy Prophet(sa) and shall be one of the members of his Ummah. In this regard, the Holy Qur`ān and Hadīth guide us that a Prophet can be a member of the Ummah of an earlier Prophet but not of a Prophet after him.
Ibrahīm(as) —a Jew or a Christian
O People of the Book! Why do you dispute concerning Abraham, when the Torah and the Gospel were not revealed till after him? Will you not then understand? (3:66)
In this verse Allāh draws the attention of Jews and Christians by mentioning a principle that religious groups are formed after the revelation of a Divine Book. Thus Jewish and Christian communities came into being after the revelation of the Torah and the Gospel. Whereas Ibrahīm(as) was before the revelation of the Torah and the Gospel, i.e., before the formation of Jewish and Christian communities. Thus he could not be considered a member of both of these groups.
Ibrahīm as—a Member of Noah’s(as) Group
And, verily, of his party was Abraham; (37:84)
As both Prophet Moses(as) and Prophet Jesus(as) came after Prophet Ibrahīm(as), thus he cannot be considered as member of Jewish and Christian communities. However, according to the above verse, he came after Prophet Noah(as), thus declared a member of Noah’s(as) community.
The Desire of Prophet Moses(as)
In the following Hadīth, it is mentioned that Prophet Moses(as) expressed his desire to become a member of Muslim Ummah. This desire was not accepted by Allāh on the ground that Prophet Moses(as) is before the formation of Muslim Ummah that shall be formed, after two thousand years, with the revelation of the Holy Qur`ān. Thus the same obstacle for Prophet Moses(as) to become a member of Muslim Ummah is for Prophet Jesus(as). Thus, he cannot become a member of the Muslim Ummah which came into being with the revelation of the Holy Qur`ān, after six hundred years of his time.
“Abu Na`eem related in “Hulya” from Anas(ra) that the Holy Prophet(sa) said that Allāh revealed to Prophet Moses(as) that I shall throw all those in hell who come to me in a state that they rejected Ahmad(sa). Prophet Moses(as) asked, O God, who is Ahmad? Allāh said that he is the best amongst all the creatures and I wrote his name on throne before the creation of heaven and earth and none of my creatures can enter Paradise unless they become member of his Ummah. Prophet Moses(as) requested that O God, appoint me a Prophet of this Ummah. Allāh said that their Prophet shall be from amongst them. Prophet Moses(as) again requested that then make me a member of this Ummah. Allāh said that you are before them and they shall be after you, but I shall join you in the House of My Majesty.” (Al-Khasaisul Kubrā by Allamā Jalāluddin Al-Sayyūtī; & Nashr-ut-Tīb Fī Zikr-un-Nabī Alhabīb, by Ashraf Alī Thanvī)
More on this topic in Jesus – a humble prophet of God