Most modern Christians do not get their norms for ethics from the Bible, and this is a good thing.
For example, as many critics of Christianity point out, nowhere do biblical authors explicitly condemn slavery. There is, of course, the whole Exodus story, and we can read it and retell it in such a way that we hear God’s sympathy with oppressed people. We can say that even ancient authors looked forward to a day of equality and freedom, when “everyone will sit under the shade of their own fig tree.” But Christian slaveowners pointed out that some scriptures told slaves to be obedient to their masters. To be obedient to God, they argued, you were supposed to accept the status quo.
The same is true for sexual ethics. Even though I really like Margaret Farley’s 7 norms for Christian sexual ethics (which are necessary for “minimal” justice), I have to admit that they are not found in the Bible: doing no harm, mutuality, commitment, none are explicitly named. Even consent is questionable. The social rules governing sexual behavior in the Hebrew Bible are all geared toward fulfilling God’s covenant with Abraham: produce lots of descendents and possess the land. Even if you take “love your neighbor as yourself” as an important principle, it’s not specific enough to tell you what kind of behaviors are good or bad. (Even hate groups claim that they are motivated by love).
While the scriptures may contain all things necessary for salvation, they do not always spell out explicitly what “things” we are supposed to learn or how to apply those things to our lives. One of my favorite stories from Genesis 38 (Judah and Tamar) points out the hypocrisy of our sexual double standards, and highlights all kinds of issues that make for really good discussion of sexual ethics. But it doesn’t say, “go and do likewise.” I believe this is why we may use the Bible as a starting point for discussions of Christian ethics, but we can only find the end in the person of Jesus Christ.
This is also why when it comes to women’s rights, or children’s rights, or economic justice, or LGBTQ rights, or church management and polity, or payday loan sharks, or immigration reform, I have little patience for my clergy colleagues who either a) dismiss these things as divisive “issues” that are somehow less important than “preaching the gospel,” or b) say “the Bible clearly says,” as if they aren’t already engaged in the act of interpretation, reading things into the text that aren’t there. Again, it’s not bad to read things into the text—it’s just important to know what those things are.
When Christians deny the possibility of marital rape, or speculate that slavery wasn’t so bad, really, they are not violating norms of biblical ethics. They are living out exactly what they’ve been taught by pastors and Sunday school curricula throughout Christendom: the Bible is all they need. We mainline clergy enable this kind of thinking unless we are clearer about our sources for Christian ethics.
For Christian ethics, what the Bible doesn’t say is as important as what it does. This is why when people say, “Just stick to the scriptures,” I cringe inside. They either do not know the scriptures as well as they think they do, or they are operating on a false premise that all of our Christian ethics come from the Bible. The Bible gives us a form and a model for doing theology and ethics, but it does not do the work of theology and ethics for us.