How far?

Every generation of Christian must face the question, “How far should I accept and adopt contemporary standards and practices? On the one hand, the Christian must not deny his faith. On the other, he must not deny his membership of society. The cause of Christ is not served if Christians appear as a group of old-fashioned people trying to retreat from the real world. Christians in fact live in the same world as their neighbors, and face the same problems. 

Leon Morris, Tyndale New Testament Commentary Series: Revelation, pg 71-72