For devotees of Santería—a centuries-old religion that mixes Yoruban ethnic traditions from the West African slaves brought to Cuba, with the Catholicism of the island’s colonial past—Dec. 17 is among the year’s holiest days. Thousands of believers flock to a small church in the Cuban village of El Rincón to celebrate Día de San Lázaro, the birthday of Babalu-Aye, the deity of illness and healing. The twins shown here have collapsed in exhaustion after walking dozens of miles to pay homage.

The Santería community is among the many spiritual groups that Spanish photographer Jordi Pizarro has documented since 2010. By focusing on religious minorities—from Orthodox Christians in Israel to Hindus of Tamil descent in Malaysia—Pizarro explores how ritual, even when violent, helps reaffirm bonds and how such performance is fundamental to a belief system. “Faith,” he says, “is strengthened through ceremony.”

Adherents of Santería, which means “the Way of the Saints,” chant in front of a statue of San Lázaro (Lazarus, a Catholic saint, who is syncretized with Babalu-Aye) in 2012. The worshippers, who requested that the statue not be photographed, make offerings, such as cigars and rum, to the deity in order to ensure good health. Thaipusam, a religious festival observed predominately by Tamil Hindus, spread from South India to British Malaya in the late 19th century when Indian laborers were brought east to work on rubber plantations. Today, more than 1 million Malaysian Hindus celebrate Thaipusam. Here, in 2014, a mother embraces her son, who stands with small cups of milk on his back—affixed to his skin with hooks—as an offering to Murugan, the Hindu god of war. A man prays at the Church of the Holy Sepulchre in Jerusalem in 2012. Located in the metropolis’s Old City, the church is among the holiest sites of Christianity because it encompasses the spot where some believe Jesus was crucified and buried.

After traveling for more than one week with a cinder block chained to his ankle, a man arrives in the outskirts of El Rincón in 2012. Acts of penitence are common on Día de San Lázaro, though this particular practice, Pizarro says, is not widespread.

During Thaipusam, devotees make a pilgrimage to the temple at Batu Caves near Kuala Lumpur. Many, like the man pictured here in 2014, pierce their skin with hooks or skewers.

During Kumbh Mela, a Hindu festival held every 12 years, tens of millions of devotees gather in Allahabad, India, to bathe for just a few minutes where the Ganges and Yamuna rivers meet. The wash is meant to cleanse people of their sins. Here, Nepalese worshippers prepare for the ritual by painting their faces with ash in 2013. A man rests in the street after making a trek from Haiti to the church in El Rincón in 2012. The marks on his legs are symbols of the Christian cross. In 2012, a woman kneels at Poland’s Holy Mount of Grabarka, where every August, thousands of Orthodox Christians travel to commemorate the Transfiguration of Christ. This site is believed to be where God protected villagers from the spread of cholera in the early 18th century.

All photographs by Jordi Pizarro