Fitting In or Standing Out?

Recently I had an opportunity to worship at First Christian Church in Huntington Beach. Their guest speaker for the evening was James Caviezel who played Christ in Mel Gibson's film "The Passion of the Christ." During his talk James mentioned that Christians are not merely to "fit into" the exisiting culture but to "stand out" as a witness to Christ and His church. In what ways do we "fit into" the norms, values and customs of our society? In what ways should Christians "stand out?" If we do live in a secular society how can Christians exert their influence?