The evangelization of the world finds itself placed in a very diversified and changing religious panorama, in which it is possible to distinguish three basic situations 171Cf. RM 33. requiring particular and precise responses. a) The situation of those "peoples, groups and socio-cultural contexts in which Christ and his Gospel are not known, or which lack Christian communities sufficiently mature to be able to incarnate the faith in their own environment and proclaim it to other groups". 172RM 33b. This situation requires a "mission ad gentes", 173RM 33b. It is important to be cognisant of the parameters (fines) that RM assigns to the "mission ad gentes". This is not restricted solely to territorial parameters (RM 37) but also to new social environments and phenomena (RM 37) such as large cities, youth, migration and to cultural areas and modern fora (RM 37) such as modern communications, science and ecology. In virtue of this a particular Church already rooted in a particular territory carries on a missio ad gentes not only ad extra but also ad intra. where missionary activity is concentrated preferably toward young people and adults. Its particular characteristic consists in the fact that it is directed to non-Christians and invites them to conversion. In this context catechesis is usually developed within the baptismal catechumenate. b) There are, moreover, situations in which, in a definite socio-cultural context, "there are Christian communities with adequate and solid ecclesial structures. They are fervent in their faith and in Christian living. They bear witness to the Gospel in their surroundings and have a sense of commitment to the Universal mission". 174RM 33c. These communities demand an intense "pastoral action of the Church" since they are made up of people and families of profound Christian outlook. In such contexts it is vital that catechesis for children, adolescents and young people develop various processes of well articulated Christian initiation which permit these to arrive at adulthood with mature faith which makes evangelizers of those who have been evagelized. Also in these situations adults are also in need of different types of Christian formation. c) In many countries of established Christian tradition and sometimes in younger Churches there exists "an intermediate situation", 175RM 33d. where "entire groups of the baptized have lost a living sense of the faith, or even no longer consider themselves members of the Church and live a life far removed from Christ and his Gospel". 176Ibidem. Such situations require "a new evangelization". The peculiar nature of this situation is found in the fact that missionary activity is directed towards the baptized of all ages, who live in a religious context in which Christian points of reference are perceived purely exteriorly. Here primary proclamation and basic catechesis are priorities. The mutual connection between the activities of evangelization which correspond to these socio-religious situations.
These socio-religious situations obviously differ from each other and it is wrong to regard them as equal. Such diversity, which has always existed in the Church's mission, acquires in today's changing world a new significance. Indeed, increasingly different situations oftentimes co-exist in the same territory. In many of the great cities, for example, a situation requiring "missio ad gentes" can co-exist along with one which requires "new evangelization". Together with these there can be present in a dynamic way Christian missionary communities sustained by "comprehensive pastoral activity". Very often today, local Churches are obliged to address the entire panorama of these religious situations. "The boundaries between pastoral care of the faithful, new evangelization and specific missionary activity are not clearly definable, and it is unthinkable to create barriers between them or to put them into water-tight compartments". 177RM 34b. In fact, "each of them influences, stimulates and assists the others". 178RM 34c. The text also speaks of the mutual enrichment between the mission ad intra and the mission ad extra. In RM 59c, in the same way, it is shown how the mission ad gentes encourages people towards development, while "new evangelization" in the more developed nations brings about a clear sense of solidarity towards others. In order, therefore, to arrive at a mutual enrichment between the various activities of evangelization which can co-exist, it is useful to remember that: – Mission ad gentes, regardless of the zone or context in which it is realized, is the missionary responsibility most specifically entrusted to the Church by Jesus and thus the exemplary model for all her missionary activity. New evangelization cannot supplant or be substituted for 'the mission ad gentes,' which continues to be the paradigm and primary task of missionary activity. 179Cf. RM 31,34. – "The model for all catechesis is the baptismal catechumenate when, by specific formation, an adult converted to belief is brought to explicit profession of baptismal faith during the Paschal Vigil". 1801977 Synod, MPD 8. This catechumenal formation should inspire the other forms of catechesis in both their objectives and in their dynamism. – "Catechesis for adults, since it deals with persons who are capable of an adherence that is fully responsible, must be considered the chief form of catechesis. All the other forms, which are indeed always necessary, are in some way oriented to it". 181DCG (1971) 20; CT 43; cf. Part Four, chap. 2. This implies that the catechesis of other age groups should have it for a point of reference and should be expressed in conjunction with it, in a coherent catechetical programme suitable to meet the pastoral needs of dioceses. In this way catechesis, situated in the context of the Church's mission of evangelization and seen as an essential moment of that mission, receives from evangelization a missionary dynamic which deeply enriches it and defines its own identity. The ministry of catechesis appears, then, as a fundamental ecclesial service for the realization of the missionary mandate of Jesus.