Its not "bipolar" or depression. If you are saved you will have those struggles in your mind. The devil cannot take away our salvation but he can ruin our testimony by tempting us to do things.
I believe music is the devils BIGGEST tool. He uses music to influence so many in the wrong way.
"For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places." Ephesians 6:12
If you do not struggle with right and wrong, if you do not battle with good and bad decisions, maybe you need Jesus. Maybe you don't have Him living in you heart. The devil won't bother you if you are already one of his.
We should not act like the world, talk like the world, dress like the world or feel comfortable in this world. This world is not my home I am just passing through. I want to be different. I don't want to fit it.