Christian Culture Justification

On Sunday past I was preaching about "How to grow as a christian". Discipleship and seeing people grow to there potential in Jesus is what I'm passionate about. I was getting across that our growth albiet supernatural through the holy spirit, is a choice we make every day in our walk with Jesus. We have to choose every day what we want to stand for. An example I gave was about using God's name in vain. Most (if not all) people who don't have a relationship with Jesus do this all the time without thinking. What amazes me is that someone with a relationship with Jesus would do this.
Is it a greater or lesser sin than a lie or a murder? It's a sin! Now I have to be honest and say that for quite some time sin has not been something I've focused on. For the last couple of "seasons" my focus has been the kingdom, Jesus' lifestyle, church, Gods will etc. A focus on sin just hasn't been on my agenda. It has amazed me how some Christians justify this particular "sin". Most seem to think that because they have a relationship with God that it's ok to use his name in vain. I've given this as an example to my daughter (who's been hearing this alot in the school yard!) Imagine you phone someone you love and when they answer you hang up. Its a prank call! When we use God's name in vain it's like that. We're calling God but not wanting to talk to him. We don't like it when someone does it to us, why would God? Just because we've relationship with Jesus, it doesn't give us licence to abuse his beautiful name or his fathers! I've never liked it when people use God's name in vain but I sort of accept it when it's by those that don't have relationship with him. Those of us that do have relationship with God it's not acceptable.