At this point we turn to the principles proper to Christian morality. These presuppose and build on the principles of common human morality, treated up to now, but what they add can only be known with the light of faith. The first moral principle refers to integral human fulfillment; but integral human fulfillment, as we shall see, is fulfillment in Jesus.
Vatican I definitively teaches that the world is created for the glory of God. This does not mean God exploits us for his own fulfillment, for that would mean he somehow needed us. Rather, God’s free choice to create is an act of pure generosity. He creates us, as the Council says, “to manifest his perfection through the benefits he bestows on creatures.” We are fulfilled in manifesting his goodness in our being and actions.
God’s self-manifestation in creation has unity, the unity of the Lord Jesus: Creatures will find their proper place in Jesus’ fullness. But there is also a certain reciprocity here. Insofar as he is man, Jesus is completed by creation united under his headship. Despite this mysterious unity, however, creatures sharing in Jesus’ fullness will not ultimately be absorbed in God, as pantheism would have it; heavenly fulfillment is instead to be understood as a fellowship.
The members of the Church are joined with Jesus in three distinct ways. First, the fullness of deity present in Jesus is communicated to members of the Church by the Holy Spirit—we become children of God. Second, there is real bodily union—a profoundly mysterious reality clearly taught in the New Testament. Third, we are united by human acts—by the redemptive act of Jesus and by our response of faith and the life of faith. Each of these three modes of union with Jesus is a present fact which, however, has yet to be perfected.
Our sharing in the divine life of Jesus will reach perfection in heaven, in the beatific vision. This ought not to be understood as a purely intellectual experience, an individual act of contemplation. Scripture offers a far richer prospect, suggesting total personal experience in community with others.
Our union with Jesus in bodily life will also be perfected in heaven. St. Paul makes it clear that the new, risen life will be truly bodily, though also different from the mortal life of human bodies in this world, inasmuch as the bodies of the blessed will be suited to persons who share in divine life.
Similarly, our union with Jesus in human acts will be perfected in heaven. Jesus’ metaphor of heaven as a wedding feast underlines the aspect of fulfillment in human goods. As we have seen, human acts are spiritual entities which last; cooperating with the grace of the Holy Spirit, Christians constitute themselves now by human acts in communion with the redemptive act of Jesus. Vatican II teaches that the kingdom, though invisible, “is already present in mystery” in this world, and our human acts become part of it.
Although creatures cannot give God anything he does not already possess, there is a sense in which human goods can be shared with the divine persons. Giving human goods to God can be understood as putting them at the service of God’s intention in creating; the lives of Christians contribute their part to accomplishing the mission which the Father gave Jesus. Moreover, we must believe that when we seek to do God’s will and please him, he receives our efforts with satisfaction—somehow we return him good for the good he has given us.
Thus, the task of Christian life is this: to complete in our lives the human fulfillment already accomplished in Jesus and in him begun for all creation. God’s kingdom, already present on earth in a hidden way, must be the focus of service in Christian life. The Incarnation initiated the time of fulfillment, but divine life and truth must still reach from the Lord Jesus to all people at all times and places, and this is a gradual process. Much the same is true of the salvation of each individual: Justification is an accomplished fact, but there is a great deal in each of us that has yet to be sanctified by the lifelong task of integrating our choices with our commitment of faith and our personal vocational commitment. In this way one comes to fulfillment in Jesus, while contributing one’s life to his fullness.