The debate over the definition of marriage has risen to prominence once again due to North Carolina voter approval of a constitutional amendment that affirmed the traditional view of marriage and due to the president’s now public advocacy of a revisionist definition of marriage.
Christian reflection on this issue, as on all moral issues, must be grounded in Scripture. The Bible is unambiguous in its rejection of homosexual practice. Furthermore, given that Scripture consistently condemns illicit affections as well as actions, Christians must recognize both homosexual practice and passions as sin. That said, sexual temptation (whether homosexual or heterosexual) and sexual sin (in thought or deed) are distinct. While it is true that numerous attempts have been mounted to reinterpret Scripture’s teaching regarding homosexual practice, these attempts are neither exegetically nor hermeneutically convincing. The best treatment of the relevant passages and the best response to common arguments is Robert A. J. Gagnon, The Bible and Homosexual Practice: Texts and Hermeneutics (Abingdon, 2001).
Natural revelation certainly testifies against homosexual practice as Paul notes in Romans 1, and it may be possible to mount a natural law case against revisionist definitions of marriage as well. The best effort currently is Sherif Girgis, Robert George, and Ryan T. Anderson, “What is Marriage?” Harvard Journal of Law and Public Policy 34, no. 1 (Winter 2010): 245-87. The difficulty in appealing to natural revelation on a controversial issue is twofold. Natural revelation is always seen most clearly through the spectacles of Scripture; Scripture has a clarity that natural revelation does not have. Second, fallen people are just as prone to suppress general revelation as they are to reject special revelation. This does not vitiate natural law argumentation, however. Even if the positive argumentation for a conjugal definition of marriage is not as clear as explicit biblical statements, the argumentation may still be helpful. Furthermore, Girgis, George, and Anderson raise telling critiques against a revisionist definition. For instance, if marriage is defined in terms of two people who love each other, what logical reason is there for limiting marriage to two? They note this is not a slippery-slope argument. It is a question about coherence. Or, if civil recognition is about homosexual couples receiving legal benefits since they live in a shared domestic situation, on what ground does the government deny these benefits to two widowed brothers who now share a home and domestic responsibilities? Can a coherent alternative definition of marriage be developed. Girgis, George, and Anderson demonstrate that none has been developed thus far.
Christians should be clear both in word and deed that their concerns about redefining marriage are not limited to concerns about homosexual behavior alone. Nor do their concerns extend only to so-called slippery slope situations: polyandry, polygamy, or incestuous marriages. Christians are concerned about rises in divorces (and about no-fault divorce law), in cohabitation, and in out of wedlock pregnancies. They should also be concerned about distortions in the biblical roles and responsibilities given to husbands and wives. Distortions of the biblical marital ideal are personally and societally disastrous because they run against the creational norms that God has placed in his world.
Christians must reject the claim that revising the definition of marriage is a civil rights issue for those who engage in homosexual behavior. This claim assumes that homosexual inclinations are biologically determined in the same way that skin color is biologically determined. The scientific evidence for this assumption is lacking. For a recent review of the data, see Stanton L. Jones, “Same-Sex Science,” First Things (February 2012): 27-33. Even if genetic predispositions to homosexual desires are discovered, Christians should recognize that this would only confirm the Scriptural teaching that the Fall has radically affected God’s good creation and that humans are sinners from conception and beset with sinful inclinations from the time they have inclinations. See chapter 8 of Ed Welch, Blame It on the Brain (P&R, 1998) and part of David Powlinson’s essay in Psychology & Christianity: Five Views (InterVarsity, 2000) [relevant portion available here].
When the redefinition of marriage is cast as a civil rights issue it inevitably raises religious liberty issues. Will churches be permitted to refuse to perform same-sex marriage ceremonies? May homosexual practice be grounds for denying employment in Christian organizations or for denying membership in Christian churches? If the redefined marriage becomes a civil right, it will be increasingly difficult for Christians to maintain their religious liberties with regard to biblical understandings of marriage. This being the case, why should same-sex couples who already have the freedom to cohabit, who may receive a religious recognition of their relationship from certain religious groups, and who may receive joint benefits if they work for any number of companies demand the civil government redefine marriage in such a way that large numbers of religious citizens are deprived of their freedom?
Given the scope of the discussion, citizens should be discussing the qualifications for a given activity or status to be considered a civil right. They should discuss the nature and extent of religious liberties. They should seek to understand the implications declaring something a good simply on the basis that it extends equality or liberty (for some). They should discuss not only the biblical position on marriage but the reasons why the Christian Scripture has framed marriage the way it has. But for this kind of discussion to take place religious reasoning cannot be excluded from public discussion. For this to take place opponents of the revised view of marriage cannot be denounced (intolerantly) as intolerant. There must be space for public discussion of the merits and demerits of the various proposals. It is certainly inappropriate for those advocating a revised view of marriage to shout down those who wish to have this discussion.
Most importantly, Christians should pray for all that are in authority so that they may live quiet and peaceable lives—lives that model God’s vision for marriage and family so that despite speaking evil of Christians, unbelievers will by observing the good works of Christians be saved and so glorify God when he returns to judge the world and set all things right (1 Tim. 2:2; 1 Pet. 2:12).
 Gagnon does not fall into the fundamentalist or conservative evangelical category, as is seen by his reference to some New Testament material as Deutero-Pauline.