FROM TIME TO time, I’ve had the opportunity to speak to groups of young adults. On one occasion, I asked the pastor organizing the event for topics that would be helpful for me to address. But he didn’t have anything too specific in mind, as if what mattered most at the time was filling a blank space in the schedule. “Just speak on something about relationships,” was all the guidance he could offer.

So, I made a suggestion. “Tell the group what I do for a living,” I said. “I’m a teaching pastor, and a seminary professor who helps train marriage and family therapists. Ask them to think of whatever questions they would want to ask someone like me, then gather the questions together and send them to me. I’ll sort through the questions and do my best to answer them when I come.”

Over the next couple of weeks, I received a good collection of sincere questions. I organized them into a meaningful order and brought them with me to the event, addressing them as honestly and concretely as I could. They responded with more questions. They were actively engaged; some were furiously trying to write down everything I said.

If I had to choose one word to describe the tone of the conversation, it would be “hunger”; they had a deep and unmet need for such conversation, and nowhere else to go. So many of them had been raised to be good churchgoing kids; they believed in and wanted to follow Jesus. But much of their training in the faith had been of the “Nice kids don’t do this or this” variety. They knew what not to do: don’t do drugs, don’t have sex before marriage, and so on. But when it came to having a positive vision of how to conduct themselves in relationships, things got a bit vague.

Imagine, then, a group like this reading the following words from the apostle Paul to the church in Colossae:

Put to death, therefore, whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, which is idolatry. Because of these, the wrath of God is coming. You used to walk in these ways, in the life you once lived. (Col 3:5-7, NIV)

Taken by itself, such teaching could easily reinforce the idea that Christianity is a religion of don’ts: Don’t do this, and don’t do that, or God’s gonna get ya!

And again, to be clear, Christians are indeed called to a life of holiness in which certain attitudes and behaviors should be off the table. Paul begins the list with what the New International Version translates as “sexual immorality.” The word he uses is the one from which we get the English word “pornography.” But in Paul’s context, the word can mean every kind of sexuality that is outside God’s design including having relations with prostitutes and sex outside of marriage.

But the moral landscape widens out from there. “Impurity” isn’t just about sex, but anything that makes a person morally unclean in God’s eyes; it’s not just about what we do on the outside, but who we are on the inside. That includes what Paul then calls “lust, evil desires, and greed.” Taken together, these words suggest hearts and minds that covet “earthly things” instead of seeking “things above,” as Paul warns at the beginning of the chapter.

That’s why he can collectively refer to them as idolatry. It’s not simply that certain forms of sex are forbidden or that greed and covetousness are bad, and God will one day come to angrily punish anyone guilty of them. Rather, it’s that when we set our hearts on earthly things, we make them into objects of worship; we make them our god. Jesus said as much in the Sermon on the Mount: “For where your treasure is, there your heart will be also. …You cannot serve both God and money” (Matt 6:21, 24).

All of this can set up the very real moral struggle that we as Christians face as we navigate this broken and sinful world. We know we’re not supposed to do certain things or think a certain way. But how do we stop?

The problem may have been particularly acute for the Colossians. Paul mentions sexual immorality, greed, and the like, and then says that this is how the Colossians themselves used to live. This didn’t make them moral monsters from a human point of view; it made them pagan citizens of the Roman Empire. And it’s easy to imagine how, knowing this, some folks in Colossae were teaching an outside-in kind of righteousness that was all about obeying strict religious rules.

But Paul takes a different tack. As we’ve seen, he doesn’t just tell the Colossians to stop doing bad things or thinking bad thoughts; he tells them to set their minds and hearts on things above, to aim their thoughts and desires toward heavenly things.

And when he tells them to “put to death whatever belongs to [their] earthly nature,” that command doesn’t just come out of the blue. He’s already told them more than once that, spiritually speaking, they have died and been raised with Jesus. He is their life now, not their former pagan ways.

This is where Christian morality begins: not with rules imposed from the outside in, but with the recognition of who we truly are in Christ, who we are continually becoming as we grow to be more like him. Paul’s command to put the old ways to death should probably be taken to mean to treat them as already dead. We cannot, after all, kill that nature ourselves; only God can, and he’s already done this through the cross of Jesus. But we can continually remind ourselves and even each other of the transformation that is already the deeper truth of who we are.

You’re not that person anymore, Paul tells the Colossians. And as we’ll see, he has even more to say about who they aren’t, who they don’t have to be anymore, before he tells them more about who they are to become.