Consider these questions:
1. Do I have all of the facts?
2. Am I assuming the worst?
3. Do I have any influence, authority or responsibility in this situation?
4. Do I have any knowledge or expertise in this area?
5. Can my words make a positive difference?
6. Am I speaking when I need to be silent?
7. Am I speaking from a heart of humility?
8. What does this do for my Christian witness?