Jesus knew that because of the hardness of our own hearts that from time to time brothers in Christ would have a problem with each other. We shouldn’t but Jesus knew we would and left us a simple command. “Moreover if your brother sins against you, go and tell him his fault between you and him alone. If he hears you, you have gained your brother.” (Matthew 18:15)
That is a simple command. Yet, very often Christians ignore this command. Here is how it plays. Party A does something that party B does not like. Party B then vents to party C all of what A has done. B has done the opposite of what Jesus said do therefore B is now guilty of sin. B should have went and talked to A alone.
I could make a list of excuses that B uses to justify venting to C and then show you why each is just a lie. But we don’t have enough space for all the excuses. Rather let me reword Jesus’ command, if you can’t talk to the person that has sinned against you then you can’t talk about the sin to anyone else except God. You do not get to vent to others. All that does is just make the problem worse.
Note: Seeking your pastor’s or other counselor’s advice on how to approach someone who has sinned against you is not circumventing this command. However your pastor or counselor does not need to know all the details.