Matthew 12:35-37
The good person produces good things from his storehouse of goodness. But the evil person produces bad things from his storehouse of evil.
Hebrews 4:12-13
For God's word is alive and active and sharper than any double-edged sword. It penetrates [deep enough] even to divide [a person's] soul [from his] spirit, and his joints [from his] bone marrow [Note: This is figurative language describing the penetrating effect of God's word into a person's spiritual, inner being] and is able to judge the thoughts and intentions of a person's heart.
James 1:26
If anyone considers himself to be religious and yet does not keep a tight rein on his tongue, this person is self-deceived and his religion is worthless.
James 3:2-10
For we all make mistakes in many areas [of life]. If anyone does not make a mistake in what he says, he is a perfect person, capable of keeping a tight rein on his whole life also.