The first one to plead his cause seems right, Until his neighbor comes and examines him. (Proverbs 18:17)
No matter how crystal clear and genuine an account may sound, there is always at least one thing which you do not know. There are always at least two sides to every story, and usually they are only in part. Everyone will explain their view with a bias; and everyone will hear with a bias. Therefore, be slow to receive an accusation against another. Likewise, be slow to make life-changing decisions based on a single source. Be an information gatherer. Make your judgments spiritually, as well as cognitively. Do not receive an accusation against an authority on the word of one witness. If someone makes an accusation against another, take the accuser to the accused, and let them speak in each other's presence. Nine out of ten times, the allegation will be resolved. Do this, and you will be known as a peacemaker. Do this, and your decisions will be right.