The worst sin

I was thinking about things that I do that I shouldn't this week, and I've come to the conclusion that the greatest sin we struggle with is lying. I know all sins are the same in God's eyes, but I bet we
lie more than commit any other sin, and I think it's probably the one thing that no-one could manage to give up completely.

It's also a secret sin in some respects because people don't know when you're lying or not, and it's something that can be joked about very easily ("Did you eat the cookie?" "No... " *shifty eyes*). It's difficult to have accountability for it - can you remember every time you told a lie or stretched the truth a bit yesterday?

There are blurry lines with lying as well. Where do you cross the line from playing make-believe to lying? Or telling a story to making out that it's true? What about exaggeration? Or lies of omission?

Any thoughts?