On one hand, the Bible calls on believers to be separate and distinct from the surrounding culture. In the Old Testament, the nation of Israel was set apart and distinct from the other nations. The three Hebrew young men in Daniel 1 would not eat the rich food of the king’s table while in exile in Babylon. In the New Testament, believers in Christ are, in like manner, called upon to be distinct from the world. In Romans 1:1 Paul says he was "separated to the gospel of God." In this second letter to the church at Corinth he urged: "Do not be unequally yoked with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness?" (2 Cor 6:14). Paul then echoes Isaiah 52:11: "Come out from among them and be separate, says the Lord. Do not touch what is unclean, and I will receive you" (2 Cor 6:17). Some take this stream in Scripture to an extreme. The Amish would be an example of this. They completely withdraw from the world around them. Some of our fundamentalist brethren do the same.
On the other hand, the Bible calls on believers to be an influence for good in society and the culture at large. In the Old Testament, we have a dominion mandate to "fill the earth and subdue it" (Gen 1:28). The Lord would speak to the exiles of Israel through Jeremiah to urge them to "seek the peace of the city where I have caused you to be carried away captive" (Jer 29:7). Jesus himself said that believers are to be salt and light in the world "a city set on a hill that cannot be hidden" (see Matt 5:13-15). We are not to hide our light under a basket but, "Let your light so shine before men" (see Matt 5:15-16). Paul could say that he became all things to all men so that he might win some (see 1 Cor 9:19-23). Some also take this stream in Scripture to an extreme. They are so much in the world that there is little difference between them and the surrounding culture. Many modern evangelicals would be examples of this.
What are we to do? We are to seek a balance. We are to be in the world but clearly distinct from the world. In John 17 Jesus prayed for his disciples noting that "these are in the world" (v. 11). Thus, we are to be in the world but not of it. The apostle John wrote: "Do not love the world or the things in the world" (1 John 2:15). Peter wrote: "but as He who called you is holy, you also be holy in all your conduct" (1 Peter 1:15).
A key text for understanding this balance is 1 Corinthians 5. In this chapter Paul writes to urge the church to exercise church discipline and expel an immoral brother. Some had taken his advice to mean that they were to have no contact at all with immoral people in the world. Paul clarifies: "Yet I certainly did not mean with the sexually immoral people of this world, or with the covetous, or extortioners, or idolaters, since then you would need to go out of the world" (1 Cor 5:11). We are to have high standards for the conduct of believers. We are to live in the world always seeking to evangelize it.
What about specific issues? What is the standard for modest clothing? What kind of entertainment (music, videos, etc.) and recreation is appropriate for a Christian? How should I educate my children? What professions are appropriate for a Christian to pursue? Can I play or watch competitive sports?
We are not to ignore these issues. We must prayerfully consider each one of them. We are to ask the Holy Spirit to guide our conduct in the light of the truth of God’s Word. A good passage to read as you reflect on the role of the Christian conscience in making decisions in such areas is Romans 14:1-15:13.