"Don't let the world around you squeeze you into its own mold, but let God re-mold your minds from within, so that you may prove in practice that the plan of God for you is good, meets all His demands and moves towards the goal of true maturity." (Romans 12:2 Phillips)
Jesus told us to live IN the world but not to be OF the world (see John 17:13-18). To be "in" the world means living in today's culture -- we all live in a culture -- and to be physically present to and with others. To be "of" the world means to buy into the values, morals and ethics of culture. Clearly, much of our culture is good; but also, just as clearly, some is not. We need to be alert to ways that the world tries to squeeze us into its mold -- to have us conform to its values. Having a biblical worldview will help us resist the temptations and seductions of society and help us to live in God-honoring ways.
-- Martin Marty and David Clark in Between Two Altars video series discussion guide