DIINUL-HAQ: This book explains extensively about knowing the religion of Islam as a true and comprehensive deen by discussing concepts in Islam related to the practice of worship, aqidah, and muamalah.
Praise be to Allah, Rabb and the worlds. Peace and greetings may be extended to all the messengers of Allah.

Amma ba'du:

This is an invitation to salvation, I offer it to every intelligent person in this universe - men and women - by hoping to Allah, the Most High and Almighty, to give happiness with this writing to those who have gone astray from His path, to give me a reward. and everyone who takes part in spreading it with the greatest reward, I say and Allah is the one who is asked for help:

Know, O intelligent human being, that there is no salvation and happiness for you in this life, and the afterlife after death unless you know the Rabb who created you, believe in and worship Him alone. You know the Prophet sent by Rabb to you and to all mankind. You believe in him and follow him. You know the true Dein that your Rabb ordered you to believe in and practice.

The book "Dīn al-Haq" which is in front of you, contains information on major issues, which you must know and practice, and I have mentioned several words and issues in the footnotes as additional explanations that are needed, relying on that to the words of Allah the Most High and the hadiths of His Messenger - may peace and blessings be upon him - because both are the only references to Dīnul Haq that Allah will not accept the religion of anyone other than him.

I have abandoned blind faith which has led many people astray, I have even mentioned several heretical groups which claim to be above the truth, even though in reality they are far from the truth, so that ignorant people are wary of them - either from people who are members of these groups - or apart from them, Wallāhu hasbī wa ni'mal wakīl (Allah is sufficient for me and He is the best administrator).