1. Imitating God means following Jesus, and following Jesus means joining him in his redeeming work. “Therefore be imitators of God, as beloved children. And walk in love, as Christ loved us and gave himself up for us, a fragrant offering and sacrifice to God” (Eph 5.1–2). Being redeemed by Jesus, one who accepts him in faith loves him with gratitude. This love requires keeping his commandments (see Jn 14.21); but he commands that we love one another as he loves us—that is, with a redeeming love (see Jn 15.12).
2. The only way a human being can make good his claim to be a Christian, one with Jesus, is “to walk in the same way in which he walked” (1 Jn 2.6). To follow Jesus is to make one’s own his commitment to redeem: “If any man would come after me, let him deny himself and take up his cross and follow me. For whoever would save his life will lose it; and whoever loses his life for my sake and the gospel’s will save it” (Mk 8.34–35). Jesus did not come to be served but to serve, to give his life for redemption. His followers must do likewise (see Mt 20.25–28; Mk 10.43–45). A commitment to Jesus is a commitment to help him do what he does: to communicate divine love by apostolic activity (see Jn 13.12–17).
3. The redemptive commitment of Jesus is a social act, a community-forming commitment which one joins by making the act of living faith. We are not redeemed passively, but in Jesus are provided a way by which to accept redemption freely, become God’s children, and share in the dignity of the Son of God by acting as his collaborators in redemption.
4. Yet even children of God continue to live in a sinful and largely unredeemed world, where ultimately there are only three choices: to join the world, and so abandon Jesus; to seek either to destroy evil or wholly segregate oneself from it, and so betray him by becoming a zealot or a Pharisee; or to try to convert the world with the love of Jesus, and so share in his fate. One will share his fate because not all of the sinful world accepts salvation, and that part which rejects it hates Jesus and his followers (see Jn 15.16–18; 16.1–4). “For what credit is it, if when you do wrong and are beaten for it you take it patiently? But if when you do right and suffer for it you take it patiently, you have God’s approval. For to this you have been called, because Christ also suffered for you, leaving you an example, that you should follow in his steps” (1 Pt 2.20–21).
Initially, the demand of Christian life does not seem so great. Guided by the Spirit, the Christian is not constrained by the law (see Gal 5.18). One need only avoid serious sin, by which one would separate oneself from God’s love, and freely undertake some works of love. Since one’s needy neighbor is identified with Jesus, works of love are required; whatever fulfills a human need contributes to the fulfillment being accomplished in Jesus (see Mt 25.31–46).
Because Jesus did not live a pleasant life of self-satisfaction, however, neither may we: “Let each of us please his neighbor for his good, to edify him” (Rom 15.2). Furthermore, a Christian who marries and has a family must fulfill his or her responsibilities in a world in which marriage and family life are culturally adapted to practices which are sinful; a Christian in business must face dishonest competition; a Christian in any responsible position must carry out his or her responsibilities even though others become slack about theirs. Eventually, the real situation becomes clear. The way of the cross is the only way to live without evil. One must be with Jesus or against him; one helps in his redemptive work or interferes with it (see Lk 11.23).
5. Following Jesus takes priority over everything else in life for a person who is serious about this commitment. One may not love one’s closest family in preference to Jesus (see Mt 10.37; Lk 14.26). One must sacrifice everything, even a part of one’s body, if that is what it takes to avoid temptation (see Mk 9.43–48). The kingdom is so precious that one must give up one’s whole livelihood for it (see Mt 13.33–46). Living thus, one becomes an image of Jesus and spreads his savor throughout the world (see Mt 5.13–16). Having been redeemed by Jesus, one must live redemptively; such is the vocation of every Christian.
6. Not only must those who have this vocation respond to God’s love as Jesus does, they must share in his work of revelation. To cooperate with Jesus in revealing God’s truth and love by one’s own Christian words and deeds is to live an apostolic, redemptive life.
7. By living a redemptive life in union with Jesus, one prepares a suitable sacrifice to join with his in the Mass. One’s whole Christian life becomes liturgy. Sacrifice is a gift to God. The gift God wants from us is a good life, lived in union with the good life of Jesus, and the service he wishes us to perform is to cooperate in Jesus’ redemptive work.
To live one’s Christian vocation is to live in Jesus. “In Jesus” the whole new creation exists (see 2 Cor 5.17). “He died for all, that those who live might live no longer for themselves but for him who for their sake died and was raised” (2 Cor 5.15). Every Christian shares in and contributes to Jesus’ single redemptive act. In one’s own life one completes what is lacking in Jesus’ sufferings (see Col 1.24). But is the redemptive act of Jesus not sufficient? Certainly, but as Jesus is in Christians and they in him, so his redemptive act is in their lives and by their own commitment their lives are in his redemptive act (see S.t., 3, q. 8, aa. 1, 3).
Vatican II teaches: “The apostolate is carried on through the faith, hope, and charity which the Holy Spirit diffuses in the hearts of all members of the Church. Indeed, the law of love, which is the Lord’s greatest commandment, impels all the faithful to promote God’s glory through the spread of his kingdom and to obtain for all men that eternal life which consists in knowing the only true God and him whom he sent, Jesus Christ (cf. Jn 17.3). On all Christians therefore is laid the splendid burden of working to make the divine message of salvation known and accepted by all men throughout the world” (AA 3). A few paragraphs later, the Council adds that the Church’s apostolate and that of every member is primarily to manifest the message of Jesus by words and deeds—by one’s own revealing life—and to communicate his grace (see AA 6).