Cheong Jin-suk briefly studied chemical engineering at the Seoul National University before entering the seminary in Seoul, from where he later obtained his bachelor's degree in theology, in 1954. After studying sociology in Hong Kong, he was ordained to the priesthood by Archbishop Paul Roh Ki-nam on 18 March 1961 at the Myeongdong Cathedral in Seoul.[1]
On 25 June 1970, Cheong was appointed the second Bishop of Cheongju by Pope Paul VI.[3] He was the youngest bishop in Korea at the time.[2] He received his episcopal consecration on the following 3 October from Archbishop Kinam Ro, with Bishops James Pardy, MM, and Peter Han Kong-ryel serving as co-consecrators, in the Church of the Holy Family in Cheongju. He was elected to a three-year term as president of the Korean Episcopal Conference in 1996.[2]
On his 80th birthday, 7 December 2011, Cheong lost his curial memberships. His resignation as archbishop was accepted by Pope Benedict XVI on 10 May 2012 and he was succeeded by Andrew Yeom Soo-jung.[8]
Cheong died at Saint Mary's Hospital in Seoul at the age of 89 on 27 April 2021. He had celebrated sixty years of his priesthood the previous month.[9] He had been admitted to hospital on 21 February with critical health issues such as breathing difficulties and a slight fever and his successor Cardinal Yeom Soo-jung administered the Anointing of the Sick on 22 February. By the first week of March, Cheong's condition seemed to improve upon the removal of life-sustaining equipment, barring the intravenous, with reports that his blood pressure and oxygen levels were gradually returning to normal. He was adamant that he would not have any surgery, nor would he remain connected to any equipment that would prolong his life. He also signed up for organ donation in the event of his death.[10][11]