I was brought up in a church system that believed holiness was possible if you took the Christian out of the world, with a long history of building monasteries and convents and spiritual hideaways. 

The aim was to isolate the believer—get them away from the world and allow them space to fellowship with God. If they were focused on Scripture, prayer, and worship, it would be easier for them to live holy lives.

But they soon discovered this was not a solution. Even if you take the Christian out of the world, only God can take the world out of the believer. There is a put off and a put on that must happen—an exchange. We’re not called to a walk isolated from the world, but to walk worthy—a walk in purity.

And that's why Jesus prayed, “I do not pray that You should take them out of the world, but that You should keep them from the evil one” (John 17:15). It’s possible to be in the world with the filth of the culture all around us, and to walk in such a way that honors the Lord.

This is where we are most effective, to be salt and to be light in the culture, not separate from it.

Ephesians 4 says that believers are to “put off concerning your former conduct the old man, which grows corrupt according to the deceitful lusts, and be renewed in the spirit of your mind, and that you put on the new man which was created according to God in true righteousness and holiness” (vv. 22-24).

What Paul was describing is repentance, and he compared it to getting your clothes soiled as you go through the day. They get so dirty that when you come home at night, you need to shower and change your clothes.

Now, it would be a shame if you tried to put fresh clothes on top of the dirty ones, as some Christians try to do. They maintain the old lifestyle while trying to add a few Christian virtues to it—that's like putting good clothes on over dirty clothes. You must put off the old you, your old manner of life, and put on the new man.

This is a beautiful description of repentance. And really, this is salvation. Salvation is more than acceptance. Repentance and acceptance go together. This is the putting off and putting on—turning away from something and turning to Someone.

We put on the new man in the culture, not isolated from it. We put off the activities and habits that we used to entertain, and the world sees the difference. They see you wearing clean clothes and ask, “How do I get those?”

But if we’re hidden away from the world, how can we, “Let [our] light shine before men, that they may see [our] good works and glorify [our] Father in heaven” (Matthew 5:16)? You're doing them no good. So put off and put on. Let the Lord take the world out of the believer.

“If anyone is in Christ, he is a new creation” (2 Corinthians 5:17). Put that on. Live that out. Walk that through.