BQ:  Often I've said things without thinking of the results, and the results have been discord and unhappiness. What does God say about that sort of behavior? 
 

"A fool’s lips bring strife,

And his mouth calls for blows.

Keeping away from strife is an honor for a man,

But any fool will quarrel." (Pro 18:6; 20:3)

Before we speak, we should consider whether or not it will cause strife. If it will, it's better to remain silent or think of another, wiser approach. :)