Exodus 20:16, Acts 6:8-13

"You shall not give false testimony." By lying about someone’s behavior you are denigrating their reputation and taking away their true identity. This is a command about safeguarding the truth about someone. By slandering someone you are attempting to destroy them, which is exactly what happens to Stephen when he is slandered. God is a God of truth and expects us to tell the truth about each other.