Either make the tree good, and his fruit good; or else make the tree corrupt, and his fruit corrupt: for the tree is known by his fruit.
O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh.
A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things. But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgment. For by thy words thou shalt be justified, and by thy words thou shalt be condemned.                  Matthew 12:33-37

Good trees produce good fruit. Bad trees or evil trees produce bad fruit. Men evil, and good produce fruit as well.

If a person’s heart is evil, out of that heart comes evil fruit. If a person’s heart is good they will produce good fruit.

The words we speak are coming as produce from the heart. What kind of words do we use? If we are always tearing down someone else, trying to make ourselves appear better to others then that is a fruit of evil. When we build others up over ourselves that is good fruit.

That good fruit comes from a heart that has been changed by the grace of God. That grace was put on display as Jesus Christ was nailed to the cross suffering for the sins of the world and He died there, was buried and He rose again justifying those who come to Him and changing our hearts to produce good fruit in life and words spoken.

If any be in Christ Jesus they are a new creation, old things have passed away, behold, all things have been made new.  2 Corinthians 5:17