Early life

Son was born on 28 January 1957 in Yeoncheon County, Gyeonggi Province, South Korea.^{[1][2][3][4][5]} In March 1972, he commenced his secondary education at Songsin High School, a minor seminary in Seoul, the capital and largest city in South Korea.^[2] After graduating in April 1975, he entered the major seminary at the Catholic University of Korea, graduating in April 1979.^[2][3][5] Beginning in October 1982, he attended the University of Innsbruck in Innsbruck, Austria, graduating in April 1986 with a Licentiate of Sacred Theology in dogmatic theology.^[2][3] After ordination back in South Korea, he returned to the University of Innsbruck, graduating in 1992 with a Doctor of Sacred Theology.^[2][3][5] After returned to South Korea and serving as pastor at a parish for two years, he returned to study at the Catholic University of Korea in March 1993, earning a Doctor of Divinity in dogmatic theology, graduating in February 1996.^[2][3]

Priesthood

Son was ordained a priest on 4 July 1986, several months after returning from his studies in the University of Innsbruck in Austria.^[1][2][4] After returning to Austria from 1986 to 1992 to continue his studies, he returned to South Korea in October 1992, and began serving as pastor at the parish in the Yongsan district of Seoul.^[2] He was pastor there until September 1994, and from 1993 to 1996 he was concurrently pursuing his doctorate at the Catholic University of Seoul.^[2] In September 1994, he became a professor of theology at the major seminary at the Catholic University of Seoul, teaching and running the seminary library until his appointment as bishop in 2015.^[2][4]

In addition to teaching, Son held a variety of other offices and positions within the Archdiocese of Seoul.^[2] From 2004 to November 2015, he was a member of the Committee for the Doctrine of the Faith of the Catholic Bishops' Conference of South Korea, serving as secretary of the committee from December 2005 to February 2014.^[2][3][5] He also served on the Episcopal Commission for the Causes of Beatification and Canonization.^[5] From August 2012 to August 2015, he was pastoral director of the Archdiocese of Seoul, and from September 2012 to August 2015 he served as a secretary of the bishops' conference's Committee for the Lay Apostolate.^[2][3][5]

Episcopacy

On 14 July 2015, Son was appointed Titular Bishop of Camplum and Auxiliary Bishop of Seoul by Pope Francis.^[1][2][3] His episcopal ordination took place on 28 August 2015,^[2][4] with Archbishop of Seoul Andrew Yeom Soo-jung serving as principal consecrator, and auxiliary bishops of Seoul Timothy Yu Gyoung-chon and Peter Chung Soon-taek serving as co-consecrators.^[1] Since 15 March 2016, Son has served as President of the Committee for the Doctrine of the Faith for the Catholic Bishop's Conference, and a member of the Episcopal Commission for Doctrine.^[2]