Cornelius Michael Thissen, the sixth of the twelve children of Clara Anna Huelskamp and Cornelius Aloysius Thissen, was born in Kingman, Kansas, on March 1, 1936. His elementary education was at St. Patrick Grade School in Kingman and, after graduating from Kingman Public High School, he spent two years at Loras College, Dubuque, Iowa, as a candidate for the Order. He was received as a novice at St. Peter Martyr Priory, Winona, Minnesota, on August 30, 1956, and was given the religious name Kevin.

On September 16, 1957, Kevin made his first profession at St. Peter Martyr Priory and was transferred to St. Thomas Aquinas Priory, River Forest, Illinois, for philosophical studies, where he earned the bachelor's and master's degrees in philosophy. On September 15, 1960, he made his solemn profession at St. Thomas Aquinas Priory and was transferred to St. Rose of Lima Priory, Dubuque, Iowa, for theological studies, where he earned a master's degree in theology. He was ordained a priest there by Bishop George Biskup on April 15, 1963.

After completing his theological studies, he spent a year as associate pastor of Nativity Parish, Campti, Louisiana (1964-65) and was then assigned to teach history and sociology at Bishop Lynch High School, Dallas, Texas, for the next three years. In 1968 he began graduate studies at The Catholic University of America, Washington, D.C., obtaining a master's degree in social work in 1970. He was then assigned to the foreign mission work of the Province in Bolivia. His time there was short, for in February 1971, he was elected prior of St. Joseph Priory, Dallas, Texas. For a year he was employed by the Dallas County Mental health and Mental Retardation Center in Dallas, and in 1972 rejoined the faculty of Bishop Lynch High School as Director of Counseling Services for the high school. In 1973 he was called to serve the Province as Socius to the Provincial, a position which he held for three years. On June 15, 1976, he was named pastor of St. Dominic Parish, Denver, Colorado, where he served for eight years. On November 1, 1984, he was named pastor of St. Thomas Aquinas Parish, Houston (Sugarland), Texas, where he continued to minister until his death.

Over the years Father Kevin had a number of health problems, including open-heart surgery and hip replacement. On June 2, 2005, he died unexpectedly at St. Thomas Aquinas

Rectory, Sugarland. A funeral Mass was celebrated at the parish and his body was taken then to Chicago where a second funeral Mass was celebrated on June 8, 2005, and he was buried in the Dominican Plot at All Saints Cemetery, Des Plaines, IL.