What's Wrong with sin?

It's so hard to minister to people about sin, when they believe  the decisions they make doesn't also effect those around them.  Or the people that believe their sin isn't all that bad.  I want to challenge them to revisit who they have wronged and see how their decision has effected others.  Let's take an example, we are visual people after all.  What about the first sin ever committed, Adam and Eve.  I can see it from the world's view, it's just a piece of fruit.  They're not hurting anyone, but aren't they?  God himself gave a direct command not to eat from the tree of knowledge of Good and evil or you'll surely die (Genesis 2:16-18).   

Now I again can hear the world again say, okay they made a mistake, didn’t God overreact by kicking them out.  We have to understand that forgiveness of sins comes after confession and repentance.  Once they were caught in their sinfully situation do you think they were sorry and sought forgiveness?  Let's take a look at Genesis 3:9-13.  Adam blame God & Eve.  Eve then blamed the Serpent, and you know what happened from there.  They were kicked out, kicked out of paradise.   I wasn't even there, but I certainly feel for them.