so ,what is sin?

I was thinking about this.
Recently some one posted something on bikejournal.com. I was first to respond, and noticed that the poster had used some word definitely not associated with "Family Friendly", not mention that the poster was a member of the international Christian Cycling Club. while the post has been clean up , it got me thinking about the emails Bruce841 and I have been exchanging. To quote Bruce "I think that, like the man born blind in John 9, we have to see Jesus for who he really is, and trust him. John 14:6

Jesus asks the same question of his friends, "Who do you say I am?"

I think discerning and following are the essence of living the Christian life, but not soteriologic in nature. Once a person has the indwelling presence, they are able to yield to Him and filled with that Spirit."
So if we have the indwelling spirit, then why do do fall into sin like Paul? If god is with us, then he should prevent this, right?
On reflection, part of it is that we are too stubborn to listen. It does take a lot to hear that still, small voice calling, especially when the world has a megaphone.
Now to medtitate.
FHS,
Jana