The Tragedy of Cultural Christianity
Cultural Christianity is not a new phenomenon.
Cultural Christianity describes people who label themselves as “Christians” because they grew up in a household of Christians, agree with some of the "good teachings" of Jesus, or enjoy the community of the church without actually worshipping God, living out the gospel, or devoting themselves to the mission of the church. In many ways, Cultural Christianity is more tragic than flat-out rejection of Jesus and His Church—it is claiming association with Jesus by taking on the name "Christian" while having no saving faith.
Jesus says in Matthew 7:21-23: "Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness.’"
These verses apply directly to the initial tragedy of cultural Christianity. There are people who sit in pews every single Sunday that do not truly know Jesus. It isn’t that they need to grow in their faith; it is that they do not have saving faith. Dean Inserra rightly says, “If we’re to bring the gospel to the nations, we must first bring it to those in our pews. Unsaved ‘Christians’ need Christ.  Disciple-making does not start with bringing the believer to maturity in Christ through sharing life alongside them. No—it begins with gospel outreach.
In other words, it begins with repentance and faith in the finished work of Christ.
In many ways, the church has become a safe haven for the cultural Christian. This can only do harm to the church. The book of Colossians is all about the supremacy of Christ, and in this letter Paul communicates what this supremacy means for the church.
After saying in verse 18 of chapter 1 that Jesus is “the head of the body, the church,” he goes on in verse 23 to encourage believers to "continue in the faith, stable and steadfast, not shifting from the hope of the gospel that you heard."
This stops cultural Christianity in its tracks.
Continuing in the faith is living out this "Christianity” that one claims to possess. Cultural Christianity attempts to boil down faith to a simple title of “Christian” when in reality being a believer in the finished work of Christ affects everything about your life.
There is no perfect example of this, but think about this in relation to marriage: you have a new title of husband or wife. But this is so much more than just a title change—you have declared your absolute commitment to this person despite sickness, monetary loss, hardship, etc. Being a husband or a wife should affect every day of your life from that point forward in loving your spouse sacrificially.
Imagine if we treated it like a new title and nothing else. We would continue to live separately, make decisions separately, date others, and many other practices if it were a new title alone.
How much more does it mean for us to live out our lives as believers?
Paul continues in Colossians 2:7 to say believers must walk in Jesus their Lord, "rooted and built up in him and established in the faith." He even says at the beginning of chapter 3, "If then you have been raised with Christ, seek the things that are above, where Christ is, seated at the right hand of God. Set your minds on things that are above, not on things that are on earth. For you have died, and your life is hidden with Christ in God. When Christ who is your life appears, then you also will appear with him in glory.”
This is a completely new life.
We are not seeking what we once sought.
We are not setting our minds on what we once set our minds on.
Does this sound like a mere title change?
Paul is not describing cultural Christianity by any means—he is describing a completely new creation in Christ. The cultural Christian thinks they are safe by taking on the name “Christian,” and yet Christ is not their life. As a result, they only know death.
Repentance and faith in the finished work of Jesus will always result in a changed life. There will be fruit. The fruit does not save but is a glorious result of the life that has grasped the truth of the gospel.
We must realize the danger of cultural Christianity. It is not the same thing as saving faith. It is actually the antithesis of saving faith. Cultural Christianity results in condemnation while saving faith results in salvation. Churches must approach Cultural Christianity with the life-saving and life-changing message of the gospel. Believers must preach the gospel to themselves each day because the gospel is the reality in which they live, and they must live it.
Assessing whether you have been living out cultural Christianity takes serious self-evaluation. The point of this is not to take anything away from the righteousness of Christ being our only hope in salvation. That will always be the truth. Christ is the believer’s life. He is the source, yes, but He is also the new reality in which the believer lives. They live out Christ-filled lives. Knowing the reality of the gospel cannot and will not result in cultural Christianity.
If you have been guilty of cultural Christianity, turn to the finished work of Christ. Live as though your only hope is Christ because the truth of the gospel is just that. Love and serve His church well through disciple-making. Proclaim His goodness and grace to a hopeless world, for this is your life in Christ.
 Dean Inserra, "The Most Overlooked Mission Field in America." Read more at The Gospel Coalition.