Is it a sin to listen to music that contains swear words?

Answer:

"Do not be deceived: 'Evil company corrupts good habits'" (I Corinthians 15:33).

The problem with hanging around with sinners is that they start influencing our lives. "Blessed is the man who walks not in the counsel of the ungodly, nor stands in the path of sinners, nor sits in the seat of the scornful" (Psalms 1:1). Listening to music with swear words means you are paying attention to what is being said. Worse, because music makes words easier to remember, they are going to be easier to recall.  It is going to influence your thoughts. "For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, thefts, covetousness, wickedness, deceit, lewdness, an evil eye, blasphemy, pride, foolishness. All these evil things come from within and defile a man" (Mark 7:21-23).

Then there is the matter of your influence. How do you tell a young person that profane language is wrong when they know you listen to music with foul language? "Judge not, that you be not judged. For with what judgment you judge, you will be judged; and with the measure you use, it will be measured back to you. And why do you look at the speck in your brother's eye, but do not consider the plank in your own eye? Or how can you say to your brother, 'Let me remove the speck from your eye'; and look, a plank is in your own eye? Hypocrite! First remove the plank from your own eye, and then you will see clearly to remove the speck from your brother's eye" (Matthew 7:1-5). There has to be a consistency between what a Christian says and what he does.