Why is the entrance to the hall dedicated to the old man?

Why is the entrance of the hall dedicated to the old gentleman? The old gentleman is actually a folk coal mine god. As the main god of Taoism, it has a high reputation, a large generation and a high status, which is conducive to enhancing the visibility and industry status of the coal industry. The so-called "self-respect is up to God". The coal industry was an industry with extremely low social status at that time. Therefore, they can only make their status as a great god in the industry higher and higher in order to achieve psychological balance and comfort. Moreover, Taishang Laojun has high mana and can better protect the safety of practitioners. The coal industry is an extremely dangerous industry, and disasters such as floods, gas explosions, landslides and coal dust often occur underground. Especially in ancient society, the level of productivity was low, people's understanding of these disasters was insufficient, and their ability to prevent them was insufficient. The life of coal miners can be said to be precarious.