St. Peter Claver, who was known for his missionary work as a Jesuit priest in South America for administering and preaching the Catholic faith to slaves, was celebrated on his feast day.

“St. Peter Claver, pray for us!” Winona-Rochester Bishop Robert Barron tweeted.

St. Peter Claver was born in 1581 in Verdú, Spain, and died in Cartagena, Colombia, in 1654. He became a Jesuit priest in 1616. In Cartagena, Peter saw the horrors of the slave trade and dedicated himself to helping those enslaved, according to Britannica.

He spread the Catholic faith while taking care of the sick and keeping company with the slaves in Colombia. It is estimated that he converted and baptized over 300,000 slaves. St. Peter Claver was canonized by Pope Leo XIII and in 1896 declared him “patron of all Roman Catholic missions to African peoples” Britannica adds.

Jesuits.org outlines St. Peter Claver’s life as a missionary to slaves. In the 17th century, many European colonists continued the slave trade despite Pope Paul III’s continuous condemnation. The Jesuits (Society of Jesus) admit that their order enslaved many during St. Peter Claver’s life in the 17th century but call it a “deeply regretful chapter.” Jesuits.org says St. Peter worked with enslaved people saying, “We must speak to them with our hands before we try to speak to them with our lips.” He baptized many children on the slave ships that he lived on.

St. Peter’s humility and dedication to those less fortunate and especially to slaves led him to poses miraculous abilities, notes Jesuits.org. They claim he would heal the sick just as Christ did.

John Grondelski, writing for the National Catholic Register (NCR), notes how St. Peter Claver’s life is an example of perseverance while the Church and the state battled over the issues of slavery.

“It would still take three centuries for much of the world to recognize the incongruity between human dignity and slavery, something Claver already knew,” Grondelski says. “And slavery continues, in various forms under different names, today. Our own society, too, can be blind to its moral failings: I am certain there will be a day when people look back on the 20th and 21st century to ask, ‘How could they believe killing their unborn babies was a ‘human right?’ Perhaps we still have something to learn from Peter Claver: about persistence in our time and patience in God’s.”