Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa., Question 3 of Fatwa No.1615
Question: What is the Islaamic ruling about this new religion Ahmadis (Qadianis) and its followers?
In addition, when and where did this religion originate and what is the Islaamic ruling about people who are in favour of it?
Response: All Praise is for Allaah the One, and prayers and salutations upon His Messenger, upon his family and his companions. To proceed…
The Pakistan government has ruled these people outside the fold of Islaam; also, the Muslim World League in Makkah has passed a similar fatwa. In the gathering of the Muslim Scholars (Muslim World League) in the year 1394 A.H. (1974 A.D.), a written statement was drafted to explain the true principles of this group, how and when they started, and so on.
Very briefly, this group has declared that Mirza Ghulaam Ahmad, an Indian, is a prophet who has received revelations from Allaah and that no one will be correct in his Islaam, unless he believes in him (Mirza). He (Mirza) was born in the 13th century, but Allaah (Subhaanahu wa Ta’aala) has told us in his Book (Qur.aan) that Prophet Muhammad ﷺ is the last of the Prophets; all Muslim scholars have given a unanimous ruling that whoever makes the claim that after him ﷺ there can appear a new prophet is a disbeliever, because he will be lying about Allaah’s Book and about the hadeeth of the Prophet ﷺ which states that he ﷺ is the very last of the Prophets. In addition, this would be contrary to the consensus of the Muslim Ummah.
And with Allaah lies all success and may Allaah send prayers and salutations upon our Prophet ﷺ and his family and his companions.