He remained a practising Catholic throughout his life and was generally sympathetic to the traditionalist Catholic position but never affiliated himself with dissident groups. Luns visited the Tridentine Mass held by the Assumptionist priest Winand Kotte, who opposed the modernising policies of the Second Vatican Council, in the Saint Wilibrord Church of Utrecht in August 1971. This seems to have been something of a misunderstanding on Luns' part however, since he had never heard of Kotte's anti-Council movement and did not wish to be affiliated with it.