Making mistakes

We all make mistakes. Let's face it. None of us are perfect and there is no way that any of us can claim that we are. I recently made a mistake. I broke the trust that was given to me. I betrayed some people that I considered friends. This was the first time that this happened. I, now, realize that I shouldn't have done this, but I can't take it back. Is 'once bitten, twice shy' the way we should live or should we give people second chances? I try to give people second chances, if they are are truly sorry for making a mistake. Don't we all make mistakes?