Mirza Mahmud Ahmad believed, at one time, that Prophet Muhammad was the Last Prophet
The Qadiani Khalifa Mirza Bashir-ud-Din Mahmud Ahmad (their leader from 1914 to 1965), who originated the belief of the Qadiani Movement that prophets can come after the Holy Prophet Muhammad, himself at one time wrote that no prophet can come after the Holy Prophet Muhammad because he was the Khatam an-nabiyyin.
In 1910, two years after the death of Mirza Ghulam Ahmad, Mirza Mahmud Ahmad wrote an article entitled Najaat (Salvation) which was published in the monthly Tashhiz-ul-azhan, the magazine of which he himself was the proprietor and editor.
Shown below is the front cover of that issue (April 1910, vol. v, no. 4) in which this article appeared:
(We have highlighted the name of the editor, Mirza Bashir-ud-Din Mahmud Ahmad, and the title of the article in question.)
In this article, he explains the meaning of the Khatam an-nabiyyin verse of the Holy Quran as follows:
“In this verse God has said that the Holy Prophet Muhammad is the Khatam an-nabiyyin, and none shall come after him who may be raised to the status of prophethood, and who may abrogate his teachings and establish a new law. Nay, however many saints (auliya) there are, and righteous and pious persons, they will get all that they get through service to him. Thus God has said that the Holy Prophet’s prophethood was meant not only for his times, but that in future too no prophet would come. …
“Another point must be remembered here, namely, that in this verse God says: ‘God is ever Knower of all things’. This does not appear to have an obvious connection here because it was not necessary to say, regarding the things God has explained, that He is the Knower of everything. The fact is that the Holy Prophet’s being the Khatam an-nabiyyin contains a prophecy.
This is that before the Holy Prophet Muhammad there arose hundreds of prophets in the world that we know about and who had great success. In fact, there does not appear to be any century in which, at one place or another, no claimant to prophethood could be found. So Krishna, Ramachandra, Buddha, Confucius, Zoroaster, Moses and Jesus are those whose followers still exist in the world, and are forcefully doing their work, each group putting forward the claim of its truth. But thirteen hundred years have passed since the Holy Prophet’s claim, and no one who claimed prophethood has ever attained success. After all, prior to his time people used to claim prophethood, and many of them were successful, whom we believe to be true. But why has this arrangement stopped with his advent? Why is no one successful now? Obviously because of the prophecy that he is the Khatam an-nabiyyin. Now we ask the opponents of Islam, what greater sign can there be than the fact that, after the Holy Prophet, no person who claimed prophethood was successful. It is this which is referred to in the words: ‘God is ever Knower of all things’. That is to say, We have made him Khatam an-nabiyyin and We know that no prophet would come after him, and any liar making such a claim would be destroyed. This, therefore, is a historical prophecy which no one can possibly refute.”
It is clearly stated in this article that:
1) none shall come after him [Prophet Muhammad] who may be raised to the status of prophethood”
2) Those who come after him among the Muslims are the auliya or saints.
3) “the Holy Prophet’s prophethood was meant not only for his times, but that in future too no prophet would come”
4) what greater sign can there be than the fact that, after the Holy Prophet, no person who claimed prophethood was successful …”
5) God says in the Quran that “We know that no prophet would come after him, and any liar making such a claim would be destroyed”.
This proves conclusively that the Qadiani belief that prophets can come after the Holy Prophet Muhammad and that Mirza Ghulam Ahmad was a prophet, was developed sometime after 1910, while Mirza Ghulam Ahmad had died in May 1908, This Rejects all the false grounds of the existence of Qadianiat from their own litrature.
(Ref provided by Br. Majzoob : This has been taken from the official Qadiani Site for Jamat-e-Ahmadya lahore if someone has doubt).