Mistakes

Making Mistakes is the one thing im a Master at..
Knowing I have crossed the line of wrong doing, Usually fully aware but with the atitude that It doesnt matter..
Usually When I make a mistake, I make up for it, by apologizing fixing it or whatever..

But what do you do when your not the one making a mistake... What do you do when you are witnessing it and sitting back and not doing anything. Does that make you just as guilty?
What if its a mistake that will change the course of someones life? If you see a friend making a choice that will effect a marriage, or a child.. Knowing that its wrong..

What do you do? Im so lost and confused by what I know that i feel like I should say something.. Its shaking me to my core.. Its rattling my emotion and its making me crazy..
DO I keep my mouth shut? Or do I speak my mind??