" Without an understanding of common grace, Christians will believe they can live self-sufficiently within their own cultural enclave. Some might feel that we should go only to Christian doctors, work only with Christian lawyers, listen only to Christian counselors, or enjoy only Christian artists. Of course, all non-believers have seriously impaired spiritual vision. Yet so many of the gifts God has put in the world are given to nonbelievers. Mozart was a gift to us—whether he was a believer or not. So Christians are free to study the world of human culture in order to know more of God; for as creatures made in His image we can appreciate truth and wisdom wherever we find it. "
― Timothy J. Keller , Every Good Endeavor: Connecting Your Work to God's Plan for the World