Is it a sin to have a crush?
The word “lust” (Strong’s #1939) means to long for (rightfully or otherwise), set your heart upon, covet, desire, or long for what is forbidden.
There is no sin in noticing the attractiveness of another person. God made us so that we would be attractive to one another. However, at the moment we begin considering what it might be like to be intimate with that other person, desire has been conceived and it gives birth to sin.
“But each one is tempted when, by his own evil desire, he is dragged away and enticed. Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death.” James 1:14-15
Jesus confirmed this thought when He said that looking at someone with lust in your heart is equivalent to committing adultery (Matthew 5:28). Our Lord was warning us that according with the high standard of the true Christian, even fantasizing about an improper relationship with someone is as bad as having one because the door is being opened to the actual sin.
All of the above having been said, an innocent crush is just that—innocent. With an innocent crush there are no or few inappropriate thoughts. With lust there is a strong sexual attraction for the person. Certain kinds of crushes can lead to more serious intentions involving feelings of both love and lust, which can be sinful. Even when there is no actual physical contact with the desired person, just observing the person of interest, fantasizing about him, and developing intense feelings is dangerous since the crush has now turned into an obsession so that you are lusting in your heart (Matthew 5:28).
Is it a sin to have feelings for someone? No, it is not a sin unless your feelings become obsessive and sexual in nature.
To learn more about sin listen to, “Are We Sure Sin is Really Sinful?”