Question: "Is it wrong to have a fantasy, according to the Bible?"
Answer: Fantasies are a product of our creative minds. They may be imagined ideas, stories, visual art, inventions, fictional scenarios, or anything else we could possibly envision. We have the ability to mentally create things because we are made in the image of the ultimate Creator (Genesis 1:27). Having an imagination is not a sin. Imagining or fantasizing about things that are pleasing to God is a wonderful way to connect with the One who created us (Philippians 4:8).
However, as with all activities in life, it is important to ensure our fantasies have a good and righteous intention behind them. Philippians 4:8 says to think about things that are true, noble, right, pure, lovely, admirable, and praiseworthy. Do your fantasies align with that biblical standard?
On the other hand, if the images, scenarios, or stories in our imagination have crossed into the realm of that which would not be pleasing to God, then our fantasizing has caused us to sin (Psalm 5:4; Proverbs 15:26). Unhealthy fantasies can lead to such sins as greed, lust, covetousness, and jealousy. Dwelling on sinful fantasies could even prompt actions resulting in physical or spiritual harm to ourselves and others (Ecclesiastes 12:14).
As Christians, we must guard our hearts and minds from evil thoughts and sinful fantasies (Romans 12:2; 3 John 1:11). “Above all else, guard your heart, for everything you do flows from it” (Proverbs 4:23). Jesus instructs His followers to “watch yourselves lest your hearts be weighed down with dissipation and drunkenness and cares of this life” (Luke 21:34).
God knows our innermost fantasies (Psalm 139:2; 94:11), and there is no use trying to hide the true motivations behind our thoughts. “For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart” (Hebrews 4:12).
If you struggle against unhealthy fantasies and wish to stop, seek the Lord for help. He will always forgive the repentant heart (Psalm 139:23–24). For the Christian, even very powerful fantasies can be overcome because of the power of God to eliminate evil thoughts from our minds (2 Corinthians 10:3–5).