The council taught: "The term 'lay faithful' is here understood to mean all the faithful except those in Holy Orders and those belonging to a religious state sanctioned by the Church. Through Baptism, the lay faithful are made one body with Christ and are established among the People of God. They are in their own way made sharers in the priestly, prophetic, and kingly office of Christ. They carry out their own part in the mission of the whole Christian people with respect to the Church and the world...It belongs to the laity to seek the kingdom of God by engaging in temporal affairs and ordering them according to the plan of God" (Constitution on the Church, 31).
There are three parts to this definition. The first part speaks of the new life given us through Baptism. Baptism makes us children of our Heavenly Father. We become members of the Body of Christ, the Church. And we are consecrated as living temples of the Holy Spirit. Thus, we enter into the life of the Most Holy Trinity in the Church through Baptism.
The second part speaks of the priestly, prophetic, and kingly nature of lay life, reflecting the "threefold office of Christ" theme which runs through the council documents. We are priestly when we offer our normal, daily activities to Christ as a sacrifice, and when we bring those offerings to Mass and Holy Communion. We are prophetic when we proclaim, by example and by word when appropriate, the truth of the Gospel. We fulfill our kingly natures by freeing ourselves from the kingdom of sin, and also by re-ordering creation to its right purpose in the Lord.
The third part speaks of the secular character of the laity. The traditional Catholic approach to the laity viewed lay life in the world as having only a sociological meaning. So, a layman did religious things as a member of the Church, but civic things as a citizen. Now, the lay presence in the temporal realm is given theological meaning. Laity are the Church present in family, job, career, culture, politics, and so on. Our normal life circumstances are not just an external framework of our Catholic life. They are "a reality destined in Jesus Christ to find the fullness of their meaning" (p. 36). Where we live, work, our families, etc., are not accidental to being Catholics. They are the matter, given by God, through which His plan for our lives is formed.
The Pope reminds us of the Council's teaching that we laity, as much as priests and religious, are called to holiness. There is a "universal call to holiness." We are not "second class," when it comes to living fully for God. Before the Council, the accepted thinking was that if one really wanted to be holy, one should be a priest, sister, or brother. Lay holiness must be worked out in one's ordinary circumstances, just as is the case with one's lay apostolate. So, this holiness may be hidden from the view of most people. But personal holiness is the indispensable foundation of the Church's mission. It must be fostered if the rest of the lay apostolate is to be effective.