What is known of the religion by necessity, and is the beard among it? And what is the ruling on one who denies it being a Sunnah?

That which is known by necessity in the religion is what is known by both the common people and the elite, and it does not admit doubt. And the growing of the beard is not something known by necessity in the religion, because its ruling may be hidden from some. So, whoever denies the indication of the authentic hadiths regarding its obligation should be advised and have the proof established against them.