If you love God worldly things won't have much appeal. It's in the Bible, I John 2:15-17, TLB. "Stop loving this evil world and all that it offers you, for when you love these things you show that you do not really love God; for all these worldly things, these evil desires—the craze for sex, the ambition to buy everything that appeals to you, and the pride that comes from wealth and importance—these are not from God. They are from this evil world itself. And this world is fading away, and these evil, forbidden things will go with it, but whoever keeps doing the will of God will live forever."
You cannot enjoy worldly pleasures and be a friend of God. It's in the Bible, James 4:4, TLB. "You are like an unfaithful wife who loves her husband's enemies. Dont you realize that making friends with God's enemies—the evil pleasures of this world—makes you an enemy of God? I say it again, that if your aim is to enjoy the evil pleasure of the unsaved world, you cannot also be a friend of God."
What kind of activities are wrong? It's in the Bible, Galatians 5:19-21, TLB. "But when you follow your own wrong inclinations your lives will produce evil results: impure thoughts, eagerness for lustful pleasure, idolatry, spiritism (that is, encouraging the activity of demons), hatred and fighting, jealousy and anger, constant effort to get the best for yourself, complaints and criticisms, the feeling that everyone else is wrong except those in your own little group—and there will be wrong doctrine, envy, murder, drunkenness, wild parties, and all that sort of thing. Let me tell you again as I have before, that anyone living that sort of life will not inherit the kingdom of God."
Don't copy the popular fads of this world. It's in the Bible, Romans 12:2, TLB. "Don't copy the behavior and customs of this world, but be a new and different person with a fresh newness in all you do and think. Then you will learn from your own experience how His ways will really satisfy you."
Knowing Jesus causes us to lose interest in the world. It's in the Bible, Galatians 6:14, TLB. "As for me, God forbid that I should boast about anything except the cross of our Lord Jesus Christ. Because of that cross, my interest in all the attractive things of the world was killed long ago, and the world's interest in me is also long dead."
Avoid worldly philosophies. It's in the Bible, Colossians 2:8, TLB. "Don't let others spoil your faith and joy with their philosophies, their wrong and shallow answers built on men's thoughts and ideas, instead of on what Christ has said."
Live as though your home were in heaven. It's in the Bible, I Peter 2:11, TLB. "Dear brothers, you are only visitors here. Since your real home is in heaven, I beg you to keep away from the evil pleasures of this world; they are not for you, for they fight against your very souls."