Hylianism
Goddess-worship
The exclusive worship of the Goddess Hylia.
Long ago, before the land of Hyrule was recognized as it is today, the Goddess Hylia came to be. Using her wisdom and compassion, she descended to the barren earth and created Hyrule with the first Hero of Light by her side.
There are very few obligations that Hylia herself mandated from the people. However, it is customary to offer a prayers by the Goddess statue at least once a year with a sacrifice if it's within one's means.
Hylia's vision of paradise is a world where mortals no longer suffer because they are all willingly and happily helping each other.
Hylianism teaches that Hylia is the supreme being of the world and that by Her grace, all things came to be and function. Because She is most known for her compassion, one must first and foremost live a life dedicated to helping their fellows in anyway possible and/or necessary.
A great evil in the form of Ganon will rise, and it is up to the princess that bears the Goddess's blood in her veins, and well as the Hero of Legend, to defend Hylia's beloved world from this evil.
Statues depicting Hylia's likeness are generally where people go to worship and pray.
Typically, people offer sacrifices and prayer to the Goddess statues on an individual or family basis. During important holidays in Central City, Zelda will lead a ceremony dedicated to Hylia that denizens are welcome to participate in.
All that's required is to accept Hylia as one's patron.
Day of Remembrance/Festival of Spirits
Day of Tears
Day of Peace
Prayer and sacrifice of the fruits of one's labor to the Goddess Statues at least once a year.
Worshipers of Hylianism believe that the spirits of the truly good end up in a tier of Heaven (the Realm of Heroes) that is reserved for those whom are distinguished by the Goddess Herself. These spirits do not get to convene with the Goddess; no mortal, no matter how good, is pure enough to do so. All other spirits that are cleansed in the Realm of Spirits get to live on forever in a sphere of Heaven where they enjoy everlasting peace knowing that the Goddess is watching over them, known as the Realm of Peace.
All people who are not considered "good", i.e. especially distinguished by the Goddess, go to the Realm of Spirits where they are cleansed of their sins. How long one spends in the Underworld depends on the severity of their sins in the world. The Realm of Spirits is not a place of punishment, rather it is for self-reflection. It is a place that is either lonely or crowded, depending on the sin, and after spirits are cleansed, they get to enjoy peace in Heaven. However, souls that refuse to be cleansed, or truly evil people, get to wander in darkness forever in the Realm of the Lost, a place that is pure nothingness.
There is also a Hell, also known as the Realm of the Damned, but there are very few people who ever existed in the world who deserve to be forever tormented there. Hell instead is the sole domain of demons that constantly and eternally fight for dominance and/or try to escape to terrorize mortalkind.
Because of this, to tell someone to "go to Hell" is a grave insult.