The essential characteristic of the lay faithful who work in the Lord's vineyard (cf. Mt 20:1-16) is the secular nature of their Christian discipleship, which is carried out precisely in the world. “It belongs to the laity to seek the kingdom of God by engaging in temporal affairs and directing them according to God's will”1139Second Vatican Ecumenical Council, Dogmatic Constitution Lumen Gentium, 31: AAS 57 (1965), 37.. By Baptism, the laity are incorporated into Christ and are made participants in his life and mission according to their specific identity. “The term ‘laity' is here understood to mean all the faithful except those in Holy Orders and those who belong to a religious state approved by the Church. That is, the faithful who, by Baptism are incorporated into Christ, are placed in the People of God and in their own way share the priestly, prophetic and kingly office of Christ, and to the best of their ability carry on the mission of the whole Christian people in the Church and in the world”1140Second Vatican Ecumenical Council, Dogmatic Constitution Lumen Gentium, 31: AAS 57 (1965), 37..
The identity of the lay faithful is born in and nourished by the sacraments of Baptism, Confirmation and the Eucharist. Baptism conforms the person to Christ, Son of the Father, first-born of every creature, sent to all as Teacher and Redeemer. Confirmation configures the individual to Christ, sent to give new life to creation and to every being through the outpouring of his Spirit. The Eucharist makes the believer a participant in the unique and perfect sacrifice that Christ offered to the Father, in his own flesh, for the salvation of the world. Lay Catholics are disciples of Christ starting with the sacraments, that is, by virtue of what God has wrought in them, marking them with the very image of his Son Jesus Christ. It is from this divine gift of grace, and not from human concession, that is born the threefold “munus” (gift and duty) that characterizes the lay person as prophet, priest and king, according to his secular nature.
It is the proper duty of the lay faithful to proclaim the Gospel with an exemplary witness of life rooted in Christ and lived in temporal realities: the family; professional commitment in the world of work, culture, science and research; the exercise of social, economic and political responsibilities. All secular human realities — both personal and social, including various environments and historical situations, as well as structures and institutions — are the context in which the lay Christian lives and works. These realities are places where God's love is received; the commitment of the lay faithful must correspond to this vision and is to be considered an expression of evangelical charity; “for the lay faithful to be present and active in the world is not only an anthropological and sociological reality, but in a specific way, a theological and ecclesiological reality as well”1141John Paul II, Post-Synodal Apostolic Exhortation Christifideles Laici, 15: AAS 81 (1989), 415..
The witness of the lay faithful is born from the gift of grace, recognized, nurtured and brought to maturity1142Cf. John Paul II, Post-Synodal Apostolic Exhortation Christifideles Laici, 24: AAS 81 (1989), 433-435.. This motivation makes their commitment in the world significant and is opposed to the characteristics of action that are proper to atheistic humanism, which lack an ultimate basis and are circumscribed within purely temporal limits. The eschatological perspective is the key that allows a correct understanding of human realities. From the standpoint of definitive goods, the lay faithful are able to engage in earthly activity according to the criteria of authenticity. Standards of living and greater economic productivity are not the only valid indicators for measuring the total fulfilment of the human person in this life, and they are of even less value when considering the life to come, “for man's horizons are not bounded only by the temporal order; living on the level of human history, he preserves the integrity of his eternal destiny”1143Second Vatican Ecumenical Council, Pastoral Constitution Gaudium et Spes, 76: AAS 58 (1966), 1099..