So far we have mainly considered common principles of morality: free choice, conscience, and natural law and its applications. Although included in the teaching of faith, these principles are accessible to unaided reason. Beginning with this chapter, our focus shifts to the principles proper to Christian morality. These presuppose and build on the common principles of morality, but what they add can be known only with the light of faith. (Some principles already treated, especially in the chapters on sin, can also be known only by faith.)
The first moral principle refers to integral human fulfillment (see 7‑F). As far as experience indicates, integral human fulfillment—a perfect human community with all of its members flourishing in all the human goods—is only an ideal. But faith teaches that this ideal is realizable and, indeed, that it is being realized as part of God’s larger plan for his creation.
Men and women who strive to do God’s will reach heaven. Heaven is a perfect community of divine and created persons, freely living in fellowship. Heaven will include not only superhuman goods but also rich fulfillment in human goods. The risen Lord Jesus is the key reality around whom God is building the heavenly community; only in Jesus can all creation, including humankind, come to fulfillment.
Thus, integral human fulfillment is fulfillment in Jesus. The hope for this fulfillment cannot help but affect the entire lives of those animated by it. Herein lies the ultimate significance of realizing human goods and of the first principle of morality which guides choices toward these goods. Here, too, we find the full meaning of an upright life: Jesus “fully reveals man to man himself and makes his supreme calling clear” (GS 22; cf. GS 24). This calling is to live in unity with Jesus and to work to bring others into community with him. Thus, the fulfillment of all things in Christ—and our personal part in it—is a basic principle of Christian morality.
Other proper principles of specifically Christian morality will be discussed in subsequent chapters. All, however, are either included in the complex reality treated in this chapter or can be understood only by reference to it. The present chapter thus provides a foundation for the remainder of this volume.1
The purpose of creation is the glory of God. This purpose will be realized in the fulfillment of all things in Jesus. Human persons are called to share in his fullness. Their share in fulfillment is to be the perfection of the ways in which Christians even now are united with Jesus: in divine life, in bodily life, and in human action. Thus there is an intrinsic relationship between Christian life in this world and in the next.
1. This chapter mainly concerns topics usually treated in eschatology. A good, recent textbook on this area: E. J. Fortman, S.J., Everlasting Life after Death (New York: Alba House, 1976). Also helpful: Michael Schmaus, Dogma, vol. 6, Justification and the Last Things (Kansas City: Sheed and Ward, 1977), 151–274.