If all Christians believed the same thing life would be so much easier. If we all sang from the same hymn sheet the church would be in a better place and our mission would be so much easier. If everyone agreed with me we'd have things sorted!! (that's joke by the way!!) There is much in the Christian life that we all agree on and that is great. However, there are areas when we disagree. Some things are cultural - or seem to be that way. Things that over here in the UK most Christians would agree are wrong seem to be accepted as OK elsewhere and vica versa.
What I'd like people's opinion on is some of the areas where Christians disagree. So what about... Horoscopes, yoga, the Masons, feng shui, acupuncture, Harry Potter, the Lottery, the list could go on. Do you have a strong opinion one way or the other? If I were to nail my colours to the mast I would say that all of the above were inconsistent with Christian living except one!!
Jesus told us that we are not "from the world" and our first and main goal should be to live a life for God. That means, being an example to those around us, telling others about God and staying in connection with God.
That said...
There sure are a lot of gray areas. I think that many things (such as rock music) is something everyone personally must decide on. For example, I know people, who get reminded of times when they took drugs when they here rock music. So I wouldn't advise them to. However, if I listen to christian rock music, it helps me focus on it.
About yoga. I've never done it, but i know a lady who did. She said that over time her focus moved more and more to yoga and away from God. If such things capture us in such a manner, we should distance us from them.
The thing I dislike about Harry Potter is this: Witches are real. And they get their power from the devil. Harry Potter says "it's okay to be a witch, it's actually really cool. you get to have power and can use it any way you want". It can have a very dangerous influence on kids. But I also think that it shouldn't be totally forbidden. At a certain age, you can explain why you as christian do not agree with this. However, it can also be important for the kids to know the story of Harry Potter so that they can explain to their friends why they don't agree.
"Everything is permissible for me - but not everything is beneficial. Everything is permissible for me - but I will not be mastered by anything." 1. Cor. 6:12
So the question I would ask in grey areas is: Does it help me serve God?