Christian moral theology informs us of who we are and who God is, so that we might know how to live with purpose. Psalm 100:3 concisely puts it: “Know that the LORD, he is God! It is he who made us, and we are his; we are his people, and the sheep of his pasture.” As sheep to the Great Shepherd (Heb. 13:20), we rely on him to guide us, to lead us into green pastures (Ps. 23:2), and to give us living waters (John 4:14; Rev. 7:17).
As we seek to live according to God’s moral norms, that is, as we engage in Christian ethics, we need to take advantage of the resources the Great Shepherd of our souls has given (1 Pet. 2:25). I count them as five primary sources.
Five Sources for Christian Moral Norms
First, he has given us his Word. Scripture outlines the moral norms and expectations of God’s justice through his Moral Law (Exod. 20:1–17) and especially through the Sermon on the Mount (Matt. 5–7) in conversation with the rest of Scripture.
Second, he has given us the gift of teachers throughout the ages (Eph. 4:11). So we pay attention to tradition, even though we do not see it as equal to scriptural authority. Its ministerial authority, however, helps us to know how God has guided his church, and we can learn from the past, as we seek instruction from those who have gone before us.
Third, Scripture and tradition attest to God’s created order being recognizable in nature (Ps. 19:1–4; Rom 1:19–20). So everyone knows basic truths like God exists and right from wrong (Rom. 2:14–15). This is different from saying that everyone knows these things perfectly, acts according to right principles, or even wills to do good. Yet natural law exists. And it provides a public or common knowledge about morality from which Christians can draw.
Fourth, God’s Spirit equips congregations to exercise various gifts for the purpose of bringing us into maturity (1 Cor. 12:7; Eph 4:12–13). In short, the congregation encourages and admonishes one another towards love and good deeds (Heb. 10:24). The church then provides the matrix for Christian moral theology, and its acts of encouragement and discipline should not be ignored.
Fifth, God created human beings with particular ends. As an acorn becomes an oak tree, so human beings in God’s image (Gen. 1:27) become godly. Holiness is thus a particular end for which we were made, so that we might be like the one who made us (1 Pet. 1:15–16). Once recognized, we can discern both an ultimate end (God) and secondary ends (all the good things in life). And hence, we practise goodness or virtue so that we might grow up into maturity as human beings. And we practise the theological virtues as gifts God gives us: faith, hope, and love (1 Cor. 13:13).
Practically then, these provide five key resources for ethical contemplation: Scripture, tradition, natural law, the church, and virtue ethics. Here, it should be noted that the church’s catechetical tradition, as well as a host of other matters, is included. But for the sake of simplicity, I have tried to lay out the simplest pattern for moral thinking that I am aware of.
Five Sources Applied to Marriage
Applied to the question of marriage, we might turn to Scripture to see that the ends of marriage are procreation, fellowship, and co-vocation (Gen. 1:28; 2:18). We might turn to tradition to see how the church applied these ends practically (e.g., Augustine’s proles, fides, and sacramentum [On the Good of Marriage 24.32]).
We can look to the experience that others have in marriage to discern patterns of truth and goodness. In other words, marriage books can be useful. We may then conceive of marriage as having particular virtues, the most important of which is love; and that love points to Christ’s union with the church (Eph. 5:31–32).
And finally, we can see that marriage is a public good with a particular ecclesial good (Christ’s union with the church), and thus congregations will find it necessary to encourage those in marriage to persist in love and good deeds, or to censure bad behaviour for the good of Christ’s church.
Much more could be said, but I think this moral framework gives the structure by which we can look at almost any moral problem and find the appropriate resources to discern between what is bad, good, and best, so that we might by rational reflection and constant practice reach the fullness of maturity in Christ (Eph. 4:13).
