There are two simple principles that Christians can use to help determine if any behavior is pleasing to God: 1) You must have a good heart. Jesus said that it’s not what goes into a person that defiles (makes them bad). Rather what’s in their hearts. From the heart comes all sorts of evil things (look at Matthew 15:15-20).
In the Old Testament, God often said that He would make a new covenant (agreement) with His people and give them a new heart. When we receive Christ, He gives us a new beginning, new nature and new heart. He gives us a capacity like never before to live right. The issue here is that Jesus needs to be number one in our heart and be our first love. For a brief presentation on how you can be controlled and empowered by His gracious Holy Spirit, please visit www.greatcom.org/spirit 2) You need to maintain a good heart. Philippians 4:7 tells us to set our minds on whatever is true and honorable and right, and to think about things that are pure and lovely and admirable. And to also think about things that are excellent and worthy of praise. Having the capacity to do what is right is only useful if our minds have right thinking.
There is a acronym that computer programmers are familiar with: GIGO (it means “Garbage in, Garbage” Simply put, if what you put in your mind is garbage, then what will come out will be garbage as well. If Jesus is number one in your life and the music fits the categories mention above, then you have freedom in Jesus to enjoy the music. Because some non-Christian songs violate the principles above, then look at the words behind the music. Be careful to not let slip into your mind something that will draw you away from a focus on Christ. And do not accept the idea that one can just listen to the music and ignore the words. Our minds, just like a tape recorder, record it all.
We have rap music with its dirty lyrics, obscene language, and violent sexual images. These words and feelings embed themselves into the minds of teenagers; words and images loaded with immoral values and impulses find a home within their hearts. Most of us who are older don’t have any idea of the obscenities and ideas communicated through this powerful medium. Taken together, multiplied millions of rap albums are sold each year, many containing the most vulgar, base, degrading, exploitative, and violent images one can imagine.
“Gangsta rap”—music that glorifies murder, rape, and drug use—now accounts for many of the hottest-selling albums on the record charts. The lyrics of most gangsta rap are indescribably vile. They mix violence, sexual imagery, and unimaginable profanity in a way that is repulsive and purposely offensive. Worse, they openly incite young people to join gangs, kill policemen, rape women, riot, and commit other acts of wanton destruction. Gangsta rap is big business. These recordings are not sold secretly out of the back of some hoodlum’s car, but marketed openly in retail stores everywhere—with slick ad campaigns designed by executives in companies like Capitol Records. And the prime target for such products are kids younger than eighteen. A whole generation is being indoctrinated with these vices. Destruction and misery are in their path. And woe to those unfortunate enough to cross their path! 
 Lutzer, E. W. (2002). Who are you to judge? learning to distinguish between truths, half-truths, and lies (136). Chicago: Moody Publishers.
 MacArthur, J., F., Jr, Mack, W. A., & Master’s College. (1997). Introduction to biblical counseling: Basic guide to the principles and practice of counseling (Electronic ed.) (110). Dallas, TX: Word Pub.