What is worldliness? What does the Bible say about worldliness?

from the old testament

• God created the world, and He said it was good (Genesis 1:10). There is nothing inherently sinful about the material world itself.
• When the word "world" is used in Scripture it sometimes refers to the created world. However, most of the time, it refers to humanity in its sinful and fallen condition whereby it opposes God and His ways (Genesis 18:25; Isaiah 24:4–6).
• Adam and Eve chose to believe Satan's lie instead of God's truth and ate the forbidden fruit in the garden of Eden (Genesis 3:6). Eve saw what was pleasing to the eye and good for food and chose the fruit over obedience to the Creator.

from the new testament

• 1 John 2:15–17 warns us about worldliness. It says: “Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him. For all that is in the world—the desires of the flesh and the desires of the eyes and pride of life—is not from the Father but is from the world. And the world is passing away along with its desires, but whoever does the will of God abides forever.”
• Worldliness can take many forms, such as the lust of the flesh, the lust of the eyes, or the pride of life (1 John 2:16).
• Jesus did not give in to worldliness but instead lived out the Father’s will (John 4:34). For example, Jesus spent forty days and nights fasting in the desert wilderness; there Satan tempted Him (Matthew 4:2–11). Unlike Adam and Eve in the paradisiacal garden of Eden, Christ responded to Satan's temptations with the truth of God's word and refused to obey Satan. His love for God triumphed over the temptations for worldly power and pleasures.
• Worldliness is exchanging the truth of God for a lie and worshiping and serving created things rather than the Creator (Romans 1:25). Instead of obeying God's command to subdue and steward the earth, mankind often loves and worships created things (Romans 1:22–23). People do the same thing today whenever they love anything more than God Himself, whether it be wealth, family, or even their own lives (Matthew 10:37–39; 19:22; John 12:25).
• Jesus gave us the greatest commandment, which is to love the Lord our God with all of our heart, mind, soul, and strength (Matthew 22:37–38).

implications for today

As Christians, we are called to imitate Christ by refusing to fall in love with this world. This does not mean that we cannot enjoy the good things that God has created (Ecclesiastes 3:13; 5:19; 1 Timothy 6:17), but we are to do so within the protective boundaries set by our loving heavenly Father and reserve our highest passions and greatest devotion for God Himself. Although we are not called to retreat from the world in monastic seclusion, we are not to love it either (1 John 2:15). In short, we are to be in the world but not of it (John 15:19; 17:15). We are not to be conformed to the world's anti-God mindset, but we are to be transformed by God's Word and Spirit so that we may know and do God's will (Romans 12:2). We must always remember that we are strangers and pilgrims in this world (Hebrews 11:13). This world is not our home. We are passing through this world to the heavenly country, where we will dwell with God forever (Hebrews 11:16; Philippians 3:20; Revelation 21:3). Like Moses, we are to choose rather to be mistreated with the people of God than to enjoy the fleeting pleasures of sin (Hebrews 11:24–26). We are to obey the Prince of Peace, Jesus Christ, rather than the prince of this world, Satan. We are called to set our minds on heavenly things and not worldly things (Colossians 3:2). We are to store up treasure in heaven rather than in this world by being rich in faith and good deeds (Matthew 6:19–21; James 2:5; 1 Timothy 6:18). We are to overcome the world through faith in Jesus Christ (1 John 5:4–5). For unlike this world, which is passing away, those who love God and do His will abide forever (1 John 2:17).