training college for social work (1977–1980), before becoming professor of fundamental theology and dogmatic theology at the Major Seminary of Ghent (1980–1996) and at the same time, Professor of Theology at the Higher Institute of Religious Sciences in Ghent, where he was also Dean, professor of Christology at the Catholic University of Leuven (1989–1992), responsible for the formation of pastoral workers in Ghent (1983–2002), episcopal vicar for theological and pastoral training in the diocese of Ghent (1992–2002). Bishop Pope John Paul II appointed him titular Bishop of Bulna and auxiliary of Mechelen-Brussel on 20 March 2002. He was consecrated on 26 May and appointed Vicar General for the vicariate of Brussels. In the Belgian bishops' conference he has been responsible for the inter-diocesan Commission for Pastoral Liturgy (Flemish and French) and a delegate to the Commission of the Bishops' Conferences of the European Community (COMECE). After Cardinal Godfried Danneels, Archbishop of Mechelen-Brussels, reached retirement age in 2008, the Nuncio to Belgium, Archbishop Karl-Josef Rauber, recommended De Kesel to succeed him, a candidacy supported by Danneels as well. Pope Benedict XVI ignored Rauber's recommendation and De Kesel remained an auxiliary. The affair was recalled in later years as Pope Francis took a different stance, making Rauber a cardinal, moving De Kesel, and then making De Kesel a cardinal. On 25 June 2010, he was appointed bishop of Bruges after the early resignation of Roger Vangheluwe and installed there on 10 July 2010. In September 2010 De Kesel said: "I think the Church must ask itself the question of whether it is appropriate to keep the mandatory character of celibacy. We could say that there are celibate priests, but that people for whom celibacy is humanly impossible should also have the chance of becoming priests." Archbishop On 6 November 2015 Pope Francis named De Kesel to succeed André-Joseph Léonard as Archbishop of Mechelen-Brussels and Primate of Belgium. He was installed at a Mass attended by the Belgian monarch on 12 December 2015. Carl E. Olson of the Catholic World Report'' regards De Kesel as a theological liberal, noting his support of Cardinal Walter Kasper's proposal to allow couples who have divorced and remarried to receive Holy Communion. Christopher Lamb calls him "a moderate in comparison with his conservative predecessor". He noted that the Bishop of Antwerp, Johan Bonny, had called for the recognition of same-sex relationships, while De Kesel by contrast said