After working for three years as a parochial vicar in Ottawa, Ontario, he was sent to Houston, Texas as a parish priest in 1999. There Riesbeck learned Spanish over seven weeks in order to celebrate mass for the congregation at predominantly Hispanic Queen of Peace parish. He was credited with a "remarkable turnaround" of the parish and its school.[2]
Riesbeck was incardinated as a member of the Companions of the Cross in 2003, and served as its Assistant General Superior. In 2010, Riesbeck was appointed Chancellor of the Diocese of Ottawa and was a judge on the Catholic Church's regional marriage tribunal. Riesbeck speaks French, English, German and Spanish.[4]
Riesbeck criticized Prime MinisterJustin Trudeau's position on abortion and suggested it would be unseemly for him to continue receiving communion, saying he takes issue with "the fact that he considers himself to be a devout Catholic but then adheres to, or advocates for, abortion." He suggested that to ameliorate his relationship with the Catholic Church, Trudeau would "have to make a public retraction of his views."[5]
On October 15, 2019, Riesbeck was appointed bishop of the Diocese of Saint John by Pope Francis.[6] Riesbeck chose the episcopal motto "Evangelii Gaudium" — meaning "joy of the gospel" — in reference to Pope Francis's apostolic exhortation of the same name.[7]