As long as you abide to the church rites without questioning, there is peace, and order (and the inquisitor leaves you be). The tenet in itself is quite vague in its beliefs. The nameless god shall not be questioned. There are a lot of church rites and although many of them may seem hollow, they must be strictly followed to keep the fate of the world in good order.
"Without ORDER there is only CHAOS, that which can not be named, (3-13) and thus thy shalt bring thine newborn child onto the church where it shall be named in the Rite of Naming; lest your child should turn into a nameless wraith or an agent of demonic proportion, and it shall be known onto the world of Order and Law, which when CHAOS reigns shall render asunder with FIRE from the hells, and the dead shall rise and plague and famine will walk the land and (6-13) therefore shalt thy pray and beg for mercy."
In this clutter of ritual and detail, the true picture has become murky at best. So people cling to the system and don't ask too many questions. It's not their place to debate and philosophise. Those are matters best left to the clergy. Most people are religious mainly for social reasons. They're a part of the social fabric formed by shared beliefs and values, but they're no zealots and flex the rules as they see fit. Ale for instance is not allowed. The book states this as "Your lips will touch no glass of ale". So they drink from mugs and bottles and believe that about covers it.