Joseph Ko Seong-un
Joseph Ko Seong-un was a martyr known for his unwavering faith during persecution. His legacy continues to inspire many.
- Feast day
- May 31
- Known as
- Martyr
- Era
- 19th-century Korea

Who they were
Joseph Ko Seong-un was born in Korea in the early 19th century, during a time when Confucian ideals dominated society and the practice of Christianity was met with severe opposition. Joseph's family converted to Catholicism, an act that put their lives at risk but instilled a strong faith in him from a young age. He grew up in an environment where the tenets of his faith were often challenged, yet he remained steadfast in his beliefs.
In 1839, a wave of violent persecution swept through Korea, targeting Christians. This was a time of great trials for believers, as the government sought to root out the growing influence of Catholicism. Joseph, along with many others, faced the threat of imprisonment and execution for their faith. Despite the dangers, he chose to stand firm, believing that his faith in Christ was worth all sacrifices.
Joseph was arrested and tortured for refusing to renounce his belief in God. His unwavering faith was put to the test during these harrowing days in prison. Accounts suggest that he endured not only physical pain but also emotional and psychological torment as his captors sought to make him betray his fellow Christians or to abandon his faith. Throughout this ordeal, Joseph remained resolute, refusing to yield as he drew strength from his prayer and deep-rooted conviction.
His martyrdom occurred on May 31, 1839, after a lengthy period of suffering. Rather than recant, he embraced the call to witness for Christ through his courage and sacrifice. Joseph Ko Seong-un became one of the martyrs of Korea, which holds a significant place in the pantheon of saints recognized by the Catholic Church.
His legacy continues not only through the liturgical commemoration of his feast day but also in the lives of many believers who find in his story a powerful testimony of faith amid persecution. Joseph's steadfastness serves as a reminder of the resilience of the human spirit when it is grounded in faith, inspiring Christians to remain strong in their convictions even in the face of adversity. His beatification was recognized officially by the Church, and he stands as a beacon of hope for those who struggle in their faith.
The blood of the martyrs is often said to be the seed of the Church, and Joseph Ko Seong-un exemplifies this truth as his sacrifice helped cultivate a deeper commitment to the Catholic faith in Korea. His story is not just one of suffering, but also of triumph—triumph that continues to resonate with the faithful today.
Remembered for
Joseph Ko Seong-un is remembered for his steadfast faith and courage during the intense persecutions of Christians in Korea. His unwavering commitment to the teachings of Christ, even in the face of death, serves as a powerful testament to the strength of belief and moral integrity.
He is particularly associated with the courage of martyrs who faced brutal circumstances, choosing to uphold their faith over the preservation of their lives. This resolve not only inspired those at the time but also continues to encourage modern believers to stand firm against challenges to their faith.
May 31
How to recognize them

- Palm branchSymbol of martyrdom, representing victory over death.
- CrossSignifying the faith for which he sacrificed his life.
- CrownRepresents the heavenly reward for enduring trials faithfully.
- BookReflects the importance of scripture in guiding one’s faith and choices.
Pray with this saint
Holy Joseph Ko Seong-un, we ask for your intercession as we strive to remain steadfast in our faith. Help us to draw strength from your example and to embrace our own crosses with courage and love. May we always seek to follow Christ as you did, never faltering in our devotion.
For your household
Incorporating the memory of Saint Joseph Ko Seong-un into family life can provide a rich opportunity for deepening faith. Families can honor his feast day on May 31 by gathering for a special meal, offering prayers, and sharing stories about his life and virtues. Parents can explain to their children the importance of steadfast faith, especially in the face of adversity, using Joseph’s story as a tangible example.
Exploring the theme of suffering and sacrifice through Joseph's life can open meaningful discussions within the family. Talk about the challenges faced in today’s world and how one can respond with a spirit of sacrifice and courage, emulating the martyr’s example. Consider creating a small family altar in Joseph’s honor, with a candle lit in his memory whenever prayers are said, reminding everyone of a life lived for God.
Children may take pride in knowing they can invoke Joseph's courage during their own times of struggle, whether in school, friendships, or personal challenges. Engage them in crafting simple prayers to Saint Joseph Ko Seong-un, giving them a sense of personal connection with this holy martyr.
Pray as a household
Carry your family in prayer
Solua gives your family a simple, faithful rhythm of prayer — one unhurried moment at a time, for the people you carry by name.
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