But that is not the way you learned Christ!— assuming that you have heard about him and were taught in him, as the truth is in Jesus,  to put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires,  and to be renewed in the spirit of your minds,  and to put on the new self, created after the likeness of God in true righteousness and holiness. - Ephesians 4:20-24 (ESV)
How do you begin to learn to live for God through Christ?
Thinking about learning to live for God through Christ may be intimidating. Perhaps you are already a baptized believer and a member of a local church who regularly participates in communion. And perhaps your Christianity has mostly consisted of attending church, trying to be good, and reading your Bible occasionally. You have never seriously considered the total claim Christ made on your life when he called you to follow him and you obeyed - at least at first, for a while.
Begin at the Beginning
Where to begin? Begin where Paul begins. You need to know Jesus, put off your old self, and be renewed in the spirit of your mind.
In the context of this passage, Paul has just written in verse 17 that the Ephesians must no longer walk as the Gentiles do. "Walking" is a term that describes a manner of life, the way a person lives. Then he lists out various things that described or characterized their walk (i.e., in the futility of their minds, darkened in their understanding, alienated from the life of God because of their hardness of heart, calloused, given to sensuality, and greedy to practice impurity; see Ephesians 2:1-3). So when we read 4:20-24, we should read them in contrast to verses 4:17-19. Everything about my old self and the way I lived must be put away. Old death must be replaced by new life.
It makes sense, then, to start with Paul's two instructions: 1) to put off the old self, which means changing our manner of life, and 2) to be renewed in the spirit of our minds. Fine and good. How do you do that?
Paul provides his own list, which is very helpful. He talks about telling the truth, being angry but not sinning, giving no opportunity to the devil, doing honest work rather than stealing, speaking gracious and/or fitting words, not grieving the Holy Spirit, and generally being kind and forgiving rather than bitter, wrathful, angry, clamorous, and slanderous. This is enough of a list to provoke all of us to examine our manner of life and make necessary changes. But Paul sums it all up with two simple instructions: 1) be an imitator of God, and 2) walk in love (cf. Eph. 5:1-2).
The Power of Habits
A lot of it comes down to habits. It can be overwhelming to understand what it means to be renewed in the spirit of your mind and put on the new self, much less actually going about doing it. I tend to think sermons are particularly helpful in this regard since a sermon can capture more of the passion and substantive zeal than a private reading and prayer time is likely, or even intended, to give.
So it helps to start with the habits. Which negative habits on Paul's list describe you in any way? Mark those. When you have compiled a list, even if it's just one of the items, pause and consider why you do it. Do you see how these things are corrupt because the desires associated with them are deceitful? They don't bring happiness. They're not good. They don't give life.
The language of putting off and putting on is used for clothing oneself in everyday life. Paul is saying that as believers are saints, they can no longer "dress" as though they were still sinners. The outward actions have to change to correspond to the inner transformation; that is, assuming the inner transformation has changed. What contradictions exist between whom God has called you to be in Christ and how you live your life?
This can be an overwhelming thing to figure out. It can seem like there's so much wrong; it is too much and there is no way to tackle such a big project. This is where I want to encourage you to start small and begin changing the little things, swapping out little bad habits for little good habits.
Ultimately, this calls for a revolution of your entire life. Remember that Paul sums it up as imitating God and walking in love. These two things leave no corner of your life untouched, from the darkest recesses of your soul to the most seemingly inconsequential act. Why is this? Because imitating God and walking in love cover everything from the deepest motivations to the smallest actions.
Habits of Grace
So where to begin? Begin with the right habits: God’s voice, God’s ear, and God’s people. These are basic categories for what is known as the means of grace or the habits of grace. David Mathis wrote a book based on these categories, which I believe are his own names for them.
Taken together, these three categories stand for all that you are responsible for pursuing to grow in the grace and knowledge of the Lord Jesus Christ.
God’s voice refers to the revelation of God, most especially in Scripture. When Scripture speaks, God speaks, for Scripture is the word of God. If you are to begin to learn to live for God through Christ, you can do no better than start right where you are and begin to match your life to God’s word. And that brings us to the next category: God’s ear.
God’s ear refers to our communication back to God on the basis of his word. This may take the form of prayer, singing, or journaling. Anything done to communicate with God is in this category. As you learn about God and how to live for him, you will also need to interact with him. He is not a distant God but has made himself near and available to us. And God calls his people to worship and serve him together, which brings us to God's people.
God's people are now, put simply, the church. In the passage preceding the one above, Paul describes the church's basic goal to be to grow up together into Christ by building itself up in love as each person fulfills their role (Eph. 4:11-16). Many believers seem to think they can go it alone in living for God, and maybe they can in some respects. But living for God through Christ means obeying God through Christ, and it is impossible to do that while ignoring God's people and the fact that we are supposed to grow up together, not grow up separate. A Christian uninvolved and uncommitted to the church is a contradiction.
I hope these thoughts give you plenty of rails to run on as it comes to beginning to learn to live for God through Christ. There is much to do! It's time to get busy about holiness.