San Bartoleños are Catholics. Resident priests lead Catholic services, perform church weddings, and teach Catholic doctrine. Folk Catholicism is practiced alongside the Catholicism of the priests, often without their approval. Protestant converts and families who became Jehovah's Witnesses in the 1940s were promptly denied access to communal lands and ejected from their homes in the Indian barrios.
The cult of San Miguel Arcángel illustrates syncretistic folk Catholicism. San Miguel has two feast days, one in early May, the other in late September, bracketing the local rainy season. Each fiesta is marked by a pilgrimage to the top of the mountain above Venustiano Carranza, a climb that takes more than an hour. Three large wooden crosses mark the place of celebration. The mountaintop rituals are led by Indians; priests do not attend. Tojolab'al speakers walk about 100 kilometers to participate, praying to San Miguel for rain. There are frequent explosions of ceremonial mortars and skyrockets, reputedly "to call the thunder." San Miguel clearly represents a rain god. Other saints and holy images also show syncretism, and Tzotzil prayers dedicated to them use the names and attributes of pre-Hispanic Maya deities.
Church-centered fiestas also have syncretistic elements. Riders wearing costumes recalling eighteenthcentury Spanish dress run ritual races at three fiestas. The beginning of Lent is marked by a costumed dance-drama reenacting the conquest of Chiapas by Spain. Saints' images are dressed in Indian clothes on their feast days. More private rites, such as the dedication of a new house, may include prayers led by a priest at one point and the sacrifice and ritual burial of a chicken after the priest leaves.
Religio-medical beliefs affect much of what San Bartoleños do. According to those beliefs, every illness and misfortune has two simultaneous causes: those visible in the normal world and those coming from supernatural actions. Visible causes call for mundane remedies, such as treatment in a modern hospital. Supernatural causes (evil eye, witchcraft, magical fright, or soul loss) require supernatural treatment by ritual specialists and traditional healers. Much of ritual behavior is connected to beliefs about supernatural effects of interpersonal relationships.
Envy causes disease directly and is the most common pernicious supernatural force in society. Involuntary evil eye may indirectly bewitch a person. Anyone who has good fortune or who exhibits wealth publicly is a natural target for envy. In consequence, San Bartoleños are reluctant to take political or ceremonial office. Publicly visible individuals who suffer no ill show by that fact that they have strong spirits and enough power to defend themselves against supernatural attack. People believe that defensive power only comes from the power to cause misfortune to others; therefore, the visible person who survives envy must have witchcraft power. Witches who do not correct or legitimate their behavior are shunned and may be killed. Becoming a principal shows great supernatural power, contained by legitimization. Nonetheless, principales are individually feared.