1) Not a matter of salvation - Key text Ephesians 2:8-9
The issue here isn't so much if what you have on your iPod or CD player will get you in or keep you out of heaven. We are not judged on our salvation by these kinds of things, only based on our standing with or against Christ as Savior & Lord. You can't earn your way to heaven by having all the latest and best Contemporary Christian music. I used the illustration of White Castle (or Krystal for the southerners) that you can live off of that but what you are putting into your system is going to have output that will keep people away from you.
2) Matter of Liberty of Conscience
Two extremes to avoid:
Legalism - That which dictates what to do/not do, expectations huge and unreasonable, rigid regulations that are fixed and unwavering. This view leans to saying "you MUST do this or you are not a good Christian."
License - This is the view that says do whatever you want because Jesus died for your sins. The more you do that may or may not be good, the more Jesus' blood covers you. This view says that you can listen to whatever without any consequence.
The tension point in the middle is Liberty. This is the view that holds that you have the freedom and ability to do things, but along with that freedom comes a great responsibility and accountability. For example, you can drive a car 120 down the road, but if you kill someone or get pulled over there are consequences. Your car can go that fast, but that doesn't mean you can do whatever you want.
There is a very good chance though, if you have to ask if it's ok, it probably isn't. Not always the case, but a general rule of thumb.
3) Vegetarians for Christ 1 Corinthians 8, Romans 14
In the early church, there was a mix of both Jewish and Greco-Roman believers. The GR believers came from a very pagan background, replete with sacrifices to idols in temples and the cultic worship of the Emperor. So, when these people get saved and come to Christ, they still have to live in an environment that caters to the pagan worship of their past. In particular, meat that had been offered to Jupiter (and the other gods) would be sold in the marketplace. They struggled if it was OK to eat this meat that had pagan stains on it. The Jewish side didn't have this struggle, because they had no regard for pagan gods.
The concept at issue here is the "weaker brother," which is where someone willingly gives up their freedoms for the sake of those who have a more incomplete/immature/growing relationship with Christ. The idea is that you won't do anything that would cause a brother/sister to stumble.
What you watch and listen to has an impact, and what will that impact be?
Personally have had to give up watching Family Guy, endorsing and supporting movies and TV shows that I cannot as a youth pastor, and not go places that would cause my testimony to be compromised. It isn't because I struggle with those things inherently, but it is something I have done in love for the sake of you.
4) Christian Distinctive 1 John 2:15-17
World and Christian are distinct, not in the Amish sense, but they are different from one another. There should be a marked difference. It isn't to be weird or outcast, but simply because we are told as Christians to not love the world or pursue the world's pleasures.
If someone saw your web history, iPod, movie shelf, or TV habits.... would they know you're a Christian?
Doesn't mean you burn all your secular everything and only listen to Praise & Worship music, but it does mean you have to ask yourself the question "Am I really living a life that is set apart?"
Think on these...
1) What are you filling yourself with?
2) Ephesians 4:1 - Are you living a life worthy of being called a Christian?
3) Read Philippians 4:8, Does what you are putting in your eyes/ears fall in line with that?
Thanks for the great questions afterwards guys, God will honor you in your search for His truth in your lives!