Have you ever felt betrayed?
And because of this you decided to stop believing in people?
So, judge that.
Do you think it's fair the innocent person pay the errors of the guilty?
You may argue that it is the way the things are. So you do not believe in justice, and it does not make any sense someone pay for whatever it was.
However, if you believe in justice and you assume, as a defense, that everyone is guilty in advance, you are condemning the righteous.
So, for the righteous you should not condemn anybody without a reason. You should give a chance for everyone who cross your way, and believe in advance.
Because if you condemn the righteous, there is no reason for the right existence, no reason for you believe in it, and even less for you fell betrayed.
Be fair with yourself.
If you believe in it, believe.