The Eucharist and the unicity of marriage
28. In the light of this intrinsic relationship between marriage, the family and the Eucharist, we can turn to several pastoral problems. The indissoluble, exclusive and faithful bond uniting Christ and the Church, which finds sacramental expression in the Eucharist, corresponds to the basic anthropological fact that man is meant to be definitively united to one woman and vice versa (cf. Gen 2:24, Mt 19:5). With this in mind, the Synod of Bishops addressed the question of pastoral practice regarding people who come to the Gospel from cultures in which polygamy is practised.
Those living in this situation who open themselves to Christian faith need to be helped to integrate their life-plan into the radical newness of Christ. During the catechumenate, Christ encounters them in their specific circumstances and calls them to embrace the full truth of love, making whatever sacrifices are necessary in order to arrive at perfect ecclesial communion. The Church accompanies them with a pastoral care that is gentle yet firm, (90) above all by showing them the light shed by the Christian mysteries on nature and on human affections.