There are two main habits of the heart; renewing the mind and putting the sinful nature to death.
Our mind is the control room for our behaviors. Whether consciously or subconsciously, deliberately or as a reaction to some stimuli or another, everything we do begins in our mind. Consequently, once we give him our heart, God is next primarily concerned with our mind. Having secured our allegiance, he now wants to give us a software update, to redefine our standard operating procedure.
Romans 12.1-2 says:
And so, dear brothers and sisters, I plead with you to give your bodies to God because of all he has done for you. Let them be a living and holy sacrifice—the kind he will find acceptable. This is truly the way to worship him. Don’t copy the behavior and customs of this world, but let God transform you into a new person by changing the way you think. Then you will learn to know God’s will for you, which is good and pleasing and perfect.
Every day, and in every moment, you must be constantly renewing your mind, letting God transform you into the person he wants you to be. This transformation is not instantaneous; it’s perpetual. It requires constant vigilance. Over time, you will notice a gap forming between the person you used to be and the person you are becoming. Your behavior will conform to your beliefs when you invite the spirit of God to change you from the inside out.
As your beliefs and behaviors continue to align, you will increasingly put to death your sinful nature.
Since you have been raised to new life with Christ, set your sights on the realities of heaven, where Christ sits in the place of honor at God’s right hand. Think about the things of heaven, not the things of earth. For you died to this life, and your real life is hidden with Christ in God. And when Christ, who is your life, is revealed to the whole world, you will share in all his glory.
So put to death the sinful, earthly things lurking within you. Have nothing to do with sexual immorality, impurity, lust, and evil desires. Don’t be greedy, for a greedy person is an idolater, worshiping the things of this world. Because of these sins, the anger of God is coming. You used to do these things when your life was still part of this world. But now is the time to get rid of anger, rage, malicious behavior, slander, and dirty language. Don’t lie to each other, for you have stripped off your old sinful nature and all its wicked deeds. Put on your new nature, and be renewed as you learn to know your Creator and become like him. In this new life, it doesn’t matter if you are a Jew or a Gentile, circumcised or uncircumcised, barbaric, uncivilized, slave, or free. Christ is all that matters, and he lives in all of us.
Since God chose you to be the holy people he loves, you must clothe yourselves with tenderhearted mercy, kindness, humility, gentleness, and patience. Make allowance for each other’s faults, and forgive anyone who offends you.
Remember, the Lord forgave you, so you must forgive others. Above all, clothe yourselves with love, which binds us all together in perfect harmony. And let the peace that comes from Christ rule in your hearts. For as members of one body you are called to live in peace. And always be thankful.
Let the message about Christ, in all its richness, fill your lives. Teach and counsel each other with all the wisdom he gives. Sing psalms and hymns and spiritual songs to God with thankful hearts. And whatever you do or say, do it as a representative of the Lord Jesus, giving thanks through him to God the Father.
Notice that the sinful nature cannot be rationalized or reasoned with or negotiated. It must be put to death. Sin must be killed.
Additionally, Christian virtue must be put on like clothing. Our culture is suspicious of people “putting on airs” or trying to look holier than they really are. I understand that suspicion; however, at some point we must acknowledge that we are not the way we are meant to be. As a result, we must put to death the sinful nature and put on the second nature—the nature of Christ.
Like Captain Sully, we have to go through hours of intentionality and practice, putting on that new nature until it becomes second nature. It becomes natural, but it starts out as a discipline.
Some have made the mistake of reducing everything Paul says here to a list of dos and don’ts. However, if all we did was adhere to these few guidelines, we’d actually miss the point of what Paul is saying.
His point is that these behaviors are clues to the second nature. The more we follow the clues; i.e., the more we discipline ourselves to put on the character of Christ, the more natural it will become.
Little children, for example, have a difficult time learning to put on pants. It requires my six-year-old daughter, Anna, about fifteen minutes every morning to put on her pants. Usually, it involves her falling over and having the dog lick her face as she giggles on the carpet. My hope is that we can shave down the pants-putting-on process to under three minutes.
It will take time, but eventually, if you keep putting your Jesus pants on every day, you will find you no longer struggle with the habits of the sinful life.
The more you practice patience, the more patient you become.
The more you practice thinking the best of people, the less you gossip about them or slander them.
The more you practice biting your tongue when angry, the easier you find it to avoid shouting matches in the office.
Arresting sinful behavior, even in little ways, demonstrates that Christ is working in you and you are being transformed. Practicing these habits of the heart helps us become God’s holy people, giving him glory through our behaviors, which is the entire point of the Christian life.