Izhar ul-Haqq

Iẓhār al-Ḥaqq is a book by Rahmatullah Kairanawi. Kairanwi had written this book in response to the allegations made by certain Christian missionaries against Islam and especially to counter the Mizan al-Haqq of Karl Gottlieb Pfander against Islam.
The book was originally written in Arabic in 1864, this six-volume book was later translated into English, Turkish, Urdu and Bengali. Christine Schirrmacher describes the book:

Urdu translation

Late Maulana Akbar Ali Khan of Darul Uloom Karachi translated the book into Urdu. Taqi Usmani wrote commentary to it. He also wrote a preface to the book which now comes as a separate book, What is Christianity? The translation and commentary have been published in three volumes.