What Keeps You From “Breaking Bad”?

I'm catching up on "Breaking Bad".  I'm somewhere near the middle of season 4. If you're unaware the show is about a high school chemistry teacher who thinks he is dying of cancer who turns himself into a meth cook in order to provide for his family after he's gone.  That's the simple set up.  It really begs the question, how far do you have to be pushed before you'd walk on the wrong side of the law.

So what keeps you "moral".  Is it god or the law or just the way you choose to live your life?  I personally just don't want anything bad enough to take advantage of other person for it.  Then there's the question (that is now being pondered in the series) of how far you'll keep going once you've gone over the line.

Care to answer?  Please do. Just remember that it may be held against you in a court of law.  Okay, that's a joke, or maybe not.  Who knows who reads these things.