Communities of the faithful should, according to the circurnstances in which they live, take part in ecumenical dialogue and the other undertakings for the restoring of Christian unity (cf. UR, 5). Catechesis should, therefore, assist in this cause (cf. UR, 6) by clearly explaining the Church’s doctrine in its entirety (cf. UR, 11) and by fostering a suitable knowledge of other confessions, both in matters where they agree with the Catholic faith, and also in matters where they differ. in doing this, it should avoid words and methods of explaining doctrine that could "lead separated brethren or anyone else into error regarding the true doctrine of the Church" (LG, 67). The order or hierarchy of the truths of Catholic teaching should be kept (cf. UR, 11; AG, 15; Ad Ecclesiam totam, May 14, 1967, AAS, 1967, pp. 574-592). However, the case for Catholic doctrine should be presented with charity as whit as with due firmness.
TheoFonsAux sources de la foi