Kill Sin or It Will Kill You

When I moved into my former house, one of the first things my dad pointed out was that my neighbor had planted Bermuda grass. I thought, “What’s the big deal? It looks fine. Better than my grass, at least.” But if there’s one thing to know about Bermuda grass, it’s that it cannot—it will not—be contained. (It’s like Nic Cage in this way.) My dad told me that without some kind of barrier around my yard, soon it too would be filled with Bermuda grass.

I struggled to keep the Bermuda grass at bay. But eventually, I just ended up moving. It was easier.

This is an example of the laws of the harvest found in Galatians 6. In verses 7 and 8, Paul says,

Do not be deceived: God is not mocked, for whatever one sows, that will he also reap. For the one who sows to his own flesh will from the flesh reap corruption, but the one who sows to the Spirit will from the Spirit reap eternal life. (ESV)

At first, we might think we already know what Paul is saying. It sounds a bit like karma. “What goes around comes around,” right? But we need to take a closer look. Because Paul isn’t proposing Christian karma. The analogy—sowing and reaping—operates very differently. It’s less like karma and more like my neighbor’s Bermuda grass.

The idea here is that what we sow multiplies, good or bad. This principle shows up everywhere in God’s creation, and it applies especially to the seeds of sin—or righteousness—that we sow into our lives. What we sow doesn’t just return to us. What we sow multiplies in and around us.

When Paul uses the phrase, “whatever one sows, that will he also reap,” he is talking about sowing sinful habits into our flesh. He says that when we do that, sin grows and grows in us until it takes over and chokes out any spiritual life we may have had.

The truth of this concept is illustrated over and over again throughout the Old Testament. In Genesis, we see how the jealousy of Joseph’s brothers can be traced back to their father, Jacob’s, extensive favoritism to Joseph’s mother, Rachel, not their mother, Leah.

And Jacob’s sin can be traced back to his father, Isaac’s, favoritism toward his other son Esau.

Isaac’s sin was sown into Jacob, which multiplied into something he sowed into his sons, which multiplied into Joseph being betrayed and sold into slavery—and ultimately the entire nation of Israel being enslaved in Egypt. One small sin of favoritism multiplied into the death, destruction, and captivity of an entire nation.

Or take 2 Samuel 13–21, one of the darkest chapters in Israel’s history. If you read through 1–2 Samuel, it’s hard to know what to do with these chapters, filled as they are with lust, betrayal, and murder. But seen as part of the law of the harvest, they begin to make more sense. King David sowed seeds of lust, betrayal, and murder. They weren’t merely paid back. They were reaped in far greater fashion. The sins of the father were multiplied in the children.


This is part of what is meant when God said in Exodus 34:7, “I will visit the sins of the parents to the third and fourth generation.” He didn’t mean the children would be held responsible for their parents’ sin (other places in Scripture make that plain), but that they would still end up suffering for it.

We shouldn’t need much convincing about this. The sobering reality we live in is that our sin affects and shapes the generations after us. Those of you from difficult homes know how long a shadow it creates. So as we look ahead, we need to know that those younger than us will learn not only to repeat our mistakes, but multiply them in greater degrees.

It should break our hearts when we see our idols replicated in those who are following us. It may not be as obvious as lust or murder. But good things, when elevated into God things, become dangerous idols. Things that have always been a little too important to us will start to manifest in others. Whether it’s success, relationship status, athleticism, wealth, or appearance, we can all inadvertently pass along these idols and perpetuate sin beyond ourselves.

Is every sin in others our fault? No, of course not. Everyone is responsible for their own decisions—and thank God sometimes those decisions end up being way better than the ones we made. Where sin abounds, grace abounds much more.

But there is a divine order to how God set things up—and stories like David’s and Isaac’s illustrate that sin works itself out according to the law of the harvest. Our sin multiplies. What a man sows he will also reap—in even greater degrees than he sowed it.

At any given moment, as John Owen said, we must be killing sin or it will be killing us, and not just us, but the generations to come.