YOU MIGHT NEVER KNOW THEM UNTIL YOU COME CLOSE

it's never fair to judge someone based on what you might have heard about them or what you assume they are...

Never take what you heard about someone hook, line and sinker, what you heard about them could be false.
Go close to that person, interact with them and know them personally before coming to a conclusion on who they are. You might be surprised that that person would be the best human you have ever come across or might even be that person that would add value to your life.

Never let what people say or think about someone who you have never met make you bitter or hate, you can never tell who they bad guy is; whether they person feeding you with lies or they center of discussion, it is solely up to you to find out.
Also, thinking someone is bad, wicked or unapproachable because of your assumption or where they are coming from is an unfair judgement. Your assumption is not fact neither do tribe tell completely who someone is.
In addition, treating someone unfairly because of what you heard about them or think they are is barbaric. Find out who they are and stop hating unnecessarily!