While it is rather simplistic to summarize the Christian life in terms of one concept, self-giving love certainly assumes central place in it. The great double commandment (Matthew 22:36–39/Mark 12:28–31) clearly states the essence of the law. Love God above all things and love your neighbour as yourself. According to John (13:34), the new commandment Jesus gives is "that you love one another." According to Paul (Galatians 6:2), the law of Christ is fulfilled when Christians bear one another's burdens.
The earliest known Christian confession (Philippians 2:5–8) presents Jesus as the one who embodies God's goodness and serves as an example of the God-pleasing life. Jesus freely relinquishes personal advantage and takes upon himself the pains and shortcomings of a fallen humanity. Care for one's neighbour assumes central place in the Christian life (Philippians 2:1–5).
The principle of self-giving love clearly delineates the ethical direction of the Christian life. However Jesus rarely gives specific instructions on what is to be done in any particular circumstance. Evidently the Christian community must find ways itself to determine what may be the most responsible course of action in any given moral dilemma.
Paul (Philippians 4:8) encouraged the Philippians to think about "whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is gracious … ." The ethics of the gospel asks Christians to act in a way that promotes the welfare of the neighbour.
John of Damascus may be helpful here. He distinguished between the "antecedent" and the "consequent" will of God. In the case of divorce, the principle would affirm that God's (antecedent) will is that there be no divorce. Since the realities of life are inescapable, it is the (consequent) will of God that divorce proceedings be made as humane and as healing as possible.
Christians cannot be content with a morality that is based on law. The law can only specify what are "the minimal requirements for civilized life," says Jersild. However to recognize the centrality of love in the Christian life does not mean that there is no longer a place for moral rules and regulations. Law "remains essential to the Christian life, even if it is not the distinguishing feature of Christian morality." It is the nature of love to be self-giving. As such, love "will often move the Christian to do more than the law requires."
In his commentary on Galatians, Hans Dieter Betz distinguishes between three kinds of ethics—the Jewish, the Hellenistic and the Pauline. He characterizes the first-century Jewish ethic as an ethic of avoidance. Here the object is to refrain from breaking the law. Betz calls the first-century Hellenistic ethic an ethic of achievement. The object here is to strive to live up to the highest moral ideals.
By contrast, Betz argues, the ethic of Paul, and not only of Paul, is an ethic of grace, that is to say, an ethic of response. According to this ethic, the Christian life is motivated by gratitude for God's abundant gifts granted freely in Jesus Christ. The object here is not the meticulous observance of individual rules. Rather, it is expected that Christians who have received such good gifts from God's gracious hands will find ways to pass on the grace they have received.
Jersild says the challenge is that one responds in a way that is responsible. This means that for Christians it is both their opportunity as well as their responsibility to God and to their neighbour to express their gratitude in loving devotion to the neighbour.