Hazrat Maulana Nur-ud-Din says reformation of people was brought about through prophets and then the saints among Muslims
Answering a question on 10 June 1908, Hazrat Maulana Nur-ud-Din explained how it was by means of prophets and then saints among Muslims that Allah brought about spiritual reform of the people of their generations, making them Godly and near to God. He clearly includes Hazrat Mirza Ghulam Ahmad among the saints who appeared in the history of Islam with the same mission.
Translated below are some extracts taken from his reply to the question. For brevity and to avoid repetition, some sentences within this passage have been omitted from this translation.
“There was a time when Allah the Most High raised Moses to the status of a Godly man, making him spiritually perfect and complete. At that time the Jews, due to the oppression and tyranny of Pharaoh and all kinds of suffering, had fallen a long way below the standard of humanity. From this condition Allah through Moses raised this nation to the level of human beings, then to Godly human beings, and then to those who are the close ones of God (muqarrab), thus manifesting His fostership (rabbubiyyat).
After a time, when the Jews no longer remained at the level at which they were left by Moses, and due to misdeeds they fell below the level of human beings, no longer believing in one God but being idolaters, no longer worshipping God but worshipping the world, and fell far distant from God, then God’s quality of fostership (rabbubiyyat) manifested its glory by raising Jesus. While the most of the self-styled Jews opposed him, many achieved high spiritual ranks through his teachings, and they became Godly and close to God.
After a passage of time they became lax and indifferent, neglected the Divine commands, and became entrapped in polytheism. The original followers of Jesus ceased to exist. A group of polluted idol-worshippers was what remained, who began to call on Jesus [as God]. Then the fostership (rabbubiyyat) of God manifested its glory by raising the Holy Prophet Muhammad. This turned the Arabs, the idol-worshippers since ancient times, about whom it is accepted that they had fallen below the level of human beings, first into humans, then into Godly humans and then into those who are close to the threshold of God.
In this way, many among the Muslims became Godly and the close ones of God through the purifying influence of the Holy Prophet, and this kept on taking place for three hundred years. Then in the times of the mujaddid of every century, by accepting the truth, the new generations became the close ones of God. There was Shah Abdul Qadir Jilani and Imam Baqir Ja‘far Sadiq by whose purifying teachings the people of their times became Godly and the close ones of God.
Then at the hands of Khwaja Muin-ud-Din Chishti, Shaikh Shahab-ud-Din Suharwardy, Khwaja Naqshband and Imam Rabbani Alfi Sani, a great many people who had fallen below the level of human beings, thousands upon thousands of them became Godly and the close ones of God. After their death, many other saints (auliya) came into the world, through whom the fostership (rabbubiyyat) of God manifested its glory and again raised thousands of people from a degraded, fallen and lower life to humans of a high standard.
In the present age, the time of our Promised Messiah, people were involved in so many innovations of shirk and unbelief. It is the fostership (rabbubiyyat) of God that a community of Godly persons has been created who at least affirm before Allah that they will place religion above the world.
Those who placed religion above the world were Adam, Noah, Abraham, Moses, Jesus, and the Holy Prophet Muhammad and all his khalifas, the generation after the Companions and the generation after that. All the holy ones who guided people towards God followed this same principle. It was the same seed that was sown in every age. They arose in different times because if the world had been made Godly and close to God once and for all then the attributes and fostership (rabbubiyyat) of God would have become suspended and redundant for future times. Also, the purity created at one time is not sufficient forever. Therefore, the means for acquiring spiritual life and purity are always required afresh.”
(Al-Hakam, 10 July 1908, p. 13)
Here Maulana Nur-ud-Din has described how the saints of Islam after the Holy Prophet Muhammad performed the same work of bringing people to God and purifying them as had been done by various prophets up to and including the Holy Prophet Muhammad. And Hazrat Mirza Ghulam Ahmad did the same work when he arose. This did not make any of those saints (auliya) into prophets. Therefore, Hazrat Mirza Ghulam Ahmad did not become a prophet by doing the work which prophets used to do.