Holy Fire when placed and lit with a flint and steel prevents enemies from spawning within a 100 block radius of itself. This effect lasts for twenty minutes and then the Holy Fire must then be reignited to prevent further mob spawning.
Holy Fire belongs to the Towa collection and does not have a prerequisite to unlock it's recipe. Holy Fire has one of, if the most expensive cost to craft requiring:
The Holy Fire prevents spawning of all mobs, no matter if they're passive, neutral, or hostile.
Mobs that wander within the Holy Fire's range aren't affected, and won't be deleted from existence.
Unlike normal campfires, Holy Fires can be broken and picked up with any tool. This means that placement of the Holy Fire isn't a permanent commitment and can be relocated as desired.
Despite that the Holy Fire prevents mobs spawns, spawning-proofing builds/areas are still a more effective method to keep these places safe as the Holy Fire extinguishes after 20 minutes. Torches and/or spawn-proofing methods are also a much cheaper alternative most of the time.
The Holy Fire makes for a great tool when it comes to mass excavation of land for it's natural resources such as terracotta.
Like campfires, the Holy Fire may be placed on top of beacon blocks allowing the player to get the desired effect and prevents mobs spawns both in the same area.