When you are college professor on a Christian campus you are often asked about your opinion as to if Behavior X is or is not a sin. The inquiring minds of college students want to know. And one can assume that their interest is more than philosophical.
There are times when the "is a sin"/"isn't a sin" binary judgment is the best way to answer the question. But life is so complex and the Christian ethical witness so diverse that at times it's a struggle to give a definitive answer. And it's at these times where I find the Wisdom literature of the Old Testament to be a better framing than the Protestant worry about escaping the wrath of an angry God.
Specifically, some things might not be sinful, but they can be decidedly stupid. Some things don't make you a bad person, but they can mark you as foolish. And some things aren't as immoral as they are immature.
Here are some advantages of using a wise/foolish frame over a not-sin/sin frame:
1. You avoid moralizing.
Sometimes you don't want to be preachy, paternalistic and schoolmarmish.
2. You force them to take responsibility.
As noted above, students aren't disinterested interlocutors. And very often they are acting in "bad faith," to use Satre's term. That is, they are running from their freedom and responsibilities. They are shopping for an endorsement from an authority figure when they need to start taking responsibility for the hard work of moral discernment and the resultant consequences of their behavior.
3. You avoid binaries.
These moral decisions often come in shades of grey. Think about, as an example, the classic youth group obsession about where "the line" is in regards to sexual activity. Sin versus not-sin is hard to impose on these underlying continua. Wise/foolish is better situated to handle the range of choices and situational complexities.
4. The frame is more holistic.
The focus on sin is often a narrow concern over God's judgment. The focus on wisdom forces you to consider a larger and longer view, how this particular behavior or path will affect me now and over the long haul. It forces you to think about things like identity and happiness. Who do I want to be? Looking back, will I feel proud of these choices? Will this behavior get me to where I want to go?
Interestingly, while it can seem that the wisdom frame is downplaying the notion of sin it is, upon consideration, making the notion of sin more robust. Think about it. Why does God prohibit certain activities? Because God is a Puritan? Or are God's commands forms of care? Spend any time at all with the Torah psalms and you quickly become aware that God isn't a schoolmarm, prude or finger-waving do-gooder. The commands of God are wisdom, patterns of life that promote psychological and social well-being.
You want adolescents and college students to avoid sin and be good?
My recommendation: Spend less time on the sin lists.
Teach them wisdom.