For every life you live, ever choice you make, every decision you take, there's always that inspirational, educational, moral and even a religious quote to back it up whether good or bad.
Now, the question is, how do you know when you are right?
I'll give you a straight forward answer which is FAITH. Doesn't necessarily mean the religious faith but obviously it comes into play. With faith and only just with faith can you determine good from bad even when greater forces oppose.