“Do not hate one another,” the Prophet Mohammad teaches. “Do not turn away from one another. Do not undercut one another.” 

Similarly, St. Paul offers in Ephesians: “Let no corrupting talk come out of your mouths, but only such as is good for building up, as fits the occasion, that it may give grace to those who hear.”

In Judaism, the concept of “hotzaat shem ra” forbids defamation. In Buddhism, backbiting and other forms of divisiveness run contrary to the values of right speech.