Come out from them and be separate!
"And be not conformed to this world: but be ye transformed by the renewing of your mind," Romans 12:2
Men of the world form their opinions of the gospel, from what they observe in its professors. There is nothing more dangerous and injurious, than when professors of religion conform to the world so far that no clear distinction can be observed between them and the worldling.
It is sometimes alleged by professors who thus accommodate themselves to the fashions and amusements of the world, that they hope by this means to render religion attractive. But this is a weak pretext, for such conformity always tends to confirm the ungodly in their carelessness. When they see professors at the theatre, or in the ballroom, their conclusion is that there is no reality in Christianity.
"Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you. And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty." 2 Corinthians 6:17-18