Christian faith is God’s gift: “By grace you have been saved through faith, and this is not your own doing; it is the gift of God—not the result of works, so that no one may boast” (Eph 2.8–9). But a Christian’s actions are not replaced by grace; rather, grace takes shape in works: “For we are what he has made us, created in Christ Jesus for good works, which God prepared beforehand to be our way of life” (Eph 2.10). The first of these good works is the act of faith itself.
Revealing himself, God enters into human history to save fallen humankind from sin and its consequences, and to call human persons to become members of the divine family. While people can choose to accept or to reject God’s proposal, to reject it is to spurn God himself. Thus, faith is necessary for salvation: “The one who believes and is baptized will be saved; but the one who does not believe will be condemned” (Mk 16.16).1
In accord with Scripture, the Catholic Church teaches that faith is the beginning of salvation.2 Indeed, it is the foundation and organizing principle for the whole of Christian life. As we shall see in chapter two, faith provides the content for hope, which motivates Christians to live for heaven and cooperate in the work of the apostolate. And as we shall see in chapter three, by incorporating fallen men and women into the new covenant, faith establishes the community which is fulfilled in eucharistic communion. Finally, as we shall see in chapter four, baptism and faith, as conversion from sin, initiate a process of growth toward holiness which must be lifelong.
If faith organizes the rest of Christian life, however, one might wonder: Given that someone has accepted the faith and through baptism become a member of the Church, how can he or she be irresponsible with respect to faith itself, as distinct from the rest of Christian life? The answer is that, although faith is a principle of Christian life which organizes all the rest, faith itself, as a human act, is a commitment, and the commitment can be radically betrayed by sinning against faith. Moreover, faith itself generates responsibilities with respect to many actions closely related to the act of faith yet distinct from it.
1. The necessity of faith for salvation does not mean that all those who have not heard the gospel are lost; if they seek religious truth and are prepared to accept it, faith is implicit in that quest and readiness (see CMP, 30.2).
2. See DS 1528–32/799–801, 1562/822, 3010/1791, 3032/1811, 3035/1814; DV 5, DH 2–3. The faith which is the beginning of salvation is living faith, that is, faith motivated by the love of God poured forth in one’s heart by the Holy Spirit (see CMP, 24.D). The Council of Trent teaches definitively that one who sins mortally after baptism can retain faith which is genuine although not living (see DS 1578/838). Such faith, remaining without love in the mortal sinner, can be called “dead faith.” Insofar as it is dead, faith is not saving (see Jas 2.18–26; cf. DS 1544/808, 1577–78/837–38). But even one whose faith is dead should fulfill all the responsibilities pertaining to faith. Hence, in what follows faith must be read according to the context as referring sometimes (as here) to living faith and sometimes (as in specifying responsibilities) to faith prescinding from the distinction between living and dead faith.