Here we learn that we all stumble in what we say at one time or another. No one is perfect in this area.
Currently as I write this, there is a very large wildfire burning in my state. It has burned some 150 homes, displacing hundreds of people. It only started from two or three lightening strikes in isolated areas, but those several lightening strike fires grew into one huge fire that tops records for Washington State.
This is what the tongue has the potential to do. Someone gossips about the pastor or someone else. The person they talked to passes it along to another and it grows bigger and bigger until it is a fire that is out of control in the church. I have seen it happen numerous times. It creates much tension among the people and is often the reason why churches lose good pastors.
We all need to be careful what we say. The old rule I heard in grade school works here:
If it's not nice,
If it's not needed,
Then don't say it.