Religion in Sliabh Grianas

Worship of the Cachstel gods predominated Sliabh Grianas since its inception in the Kingdom of Dochas. It originated as a pantheon of gods, all separately worshipped by different cults. However, the Kingdom of Dochas eventually institutionalized Cachstelism around 3400 BCE. Under this institutionalization, the population began worshipping all of the Cachstel pantheon, uniting into a greater religious body.

Cachstelism remained prominent even after Dochas's collapse, spreading across the continent. Every major empire and kingdom that followed Dochas institutionalized Cachstelism, until the inception of the Republic of Griath, the government of which was secular. During the Slieuth Empire, Cachstelism's beliefs were codified into one document, the Cachsteltola, which went on to serve as Cachstelism's primary religious text.

Worship of the Norse gods was introduced by a stray colony of Vikings in 756 CE. It is a very small minority in modern Sliabh Grianas.

After the Republic of Griath collapsed, the era of many monarchies still saw a strong Cachstelist presence, but whether or not governments institutionalized it varied from kingdom to kingdom and city-state to city-state. Tribes, following their own religions, also persisted.

Tribal and other minority religions continued to exist, but are a small minority to this day.

During the United Kingdom of Sliabh Grianas, foreign religions such as Islam, Hinduism, Buddhism, Confucianism, Taoism, and others spread to Sliabh Grianas from Asia. Later, once direct contact with Europeans was made, Christianity, Judaism, and others were introduced to Sliabh Grianas. Christianity gained strength as a major religion due to missionaries, migrations, and attempts at colonization from Europe, but still remained less widespread than Cachstelism.

During the Sliabh Grianasian Renaissance and Enlightenment, secularism and atheism increased dramatically. By 1830, roughly a fourth of Sliabh Grianasians were non-religious. This number only continued to increase through the Industrial Revolution and modern times.

As of the 2020 Sliabh Grianasian census, 24% of the population was Cachstelist, 6% Christian, 4% Muslim, 2.7% Hindu, 2.5% Buddhist, 2% indigenous/tribal religions, 0.7% Sikh, 0.6% Judaism, 1% other, 52% were non-religious (including agnostic and atheist), and 4.5% preferred not to answer.