Such statements abound in the words of the spiritually knowledgeable masters. They know that they cannot truly attain monotheism, knowledge of Allah, and certainty except by following the messengers. They may also receive rational, inferential, and demonstrative proofs, as well as inward communications and directly experienced unveilings, that confirm what the Messenger—may Allah bless him and grant him peace—has conveyed.

As Allah Most High says:

“We will show them Our signs in the horizons and within themselves until it becomes clear to them that it is the truth. Is it not sufficient that your Lord is a witness over all things?”
[Fussilat: 53]

And He says:

“Those who have been given knowledge see that what has been sent down to you from your Lord is the truth and guides to a path.”
[Sabaʾ: 6]

And He says:

“Is one who knows that what has been sent down to you from your Lord is the truth like one who is blind?”
[Al-Raʿd: 19]

You find that many who follow the path of knowledge, inquiry, and reasoning, but who have become confused and find the proofs and inferences conflicting, look favourably upon the path of those devoted to spiritual aspiration, worship, and striving, believing that realities will be revealed through it.

And many who follow the path of worship, spiritual aspiration, asceticism, and discipline,