The holy founder of the Ahmadiyya Community explained the beliefs of Ahmadis concerning whether a Prophet can still come:
“If it is asked that the Holy Prophet may peace and blessings of Allah be upon him being Khatamun Nabiyyeen, how can any other prophet arise after him? The answer is that without a doubt, no new or old prophet can come after the Holy Prophet as you believe that Jesus, being a prophet, would come in the latter days. Your doctrine is that for 40 years Jesus would continue to be a prophet and a recipient of divine revelation, a period that by far exceeds the period of the Prophethood of the Holy Prophet. Such a doctrine is, no doubt, sinful and its falsity is borne witness to by the Hadith: ‘There will be no prophet after me’.
I am utterly opposed to all such doctrines and I have firm belief in the verse:‘But he is the Messenger of Allah and Khatamun Nabiyyeen’ (33:41).
This verse contains a prophecy of which our opponents are not aware, and that prophecy is that after the Holy Prophet, may peace and blessings of Allah be upon him, all doors of prophecy have been closed and that it is not possible now that a Hindu or a Jew or a Christian or a merely formal Muslim, should be able to establish the applicability of the word prophet to himself.
All windows of Prophethood are now closed except the window of complete obedience to the Holy Prophet. Therefore, he who approaches God through this window is reflectively clothed with the same cloak of Prophethood which is the cloak of the Muhammadi Prophethood. The Prophethood of such a one is not apart and distinct from the Prophethood of the Holy Prophet, inasmuch as he does not claim it in his own right but receives everything from the fountain of the Holy Prophet, not for himself but for his glory….
Therefore the concept of Khatamun Nabiyyeen has not been contravened by my advent, but it would certainly be contravened by the advent of Jesus a second time.”
Hadhrat Mirza Ghulam Ahmad - Ek Ghalti Ka Izalah (translated into English as ‘A Misconception Removed’)