Our Scripture reading today is Proverbs 10:18, "He that hideth hatred with lying lips, and he that uttereth a slander, is a fool."
I can remember a time when if I asked someone if they were a sinner they might say, "Well, yes, but I have not killed anyone."  As if killing someone is a pretty bad sin.  Murder is definitely a wicked sin.  In the Sermon on the Mount, Jesus taught that to be angry with your brother without a cause was also a violation of the law.  Anger is more internal, but if not dealt with properly it will reveal itself in many ways.  Our verse for today makes it clear it will be seen in lying, slanderous speech.  The root cause of these hurtful words can be hatred or anger.  An individual who follows this way of living is eventually shown to be a fool.
The solution to this type of behaviour is repenting of the sin of hatred or anger and asking God to give us the strength to overcome the temptation in the future.  We must specifically ask for humility and be willing to die to self.  Galatians 2:20, "I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me."  As we meditate on Scripture, our speech will be edifying and not destructive.  Proverbs 25:11, "A word fitly spoken is like apples of gold in pictures of silver."
Have a blessed day.