Luke 6:45 NIV

Colossians 3:16 NIV
Let the message of Christ dwell among you richly as you teach and admonish one another with all wisdom through psalms, hymns, and songs from the Spirit, singing to God with gratitude in your hearts.

Colossians 4:6 NIV
Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone.

Ephesians 4:29 NIV
Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen.

Hebrews 8:10 NIV
This is the covenant I will establish with the people of Israel after that time, declares the Lord. I will put my laws in their minds and write them on their hearts. I will be their God, and they will be my people.

James 3:5-8 NIV
Likewise, the tongue is a small part of the body, but it makes great boasts. Consider what a great forest is set on fire by a small spark. The tongue also is a fire, a world of evil among the parts of the body. It corrupts the whole body, sets the whole course of one’s life on fire, and is itself set on fire by hell. All kinds of animals, birds, reptiles and sea creatures are being tamed and have been tamed by mankind, but no human being can tame the tongue. It is a restless evil, full of deadly poison.

John 7:38 NIV
Whoever believes in me, as Scripture has said, rivers of living water will flow from within them.”

Matthew 12:34-37 NIV
You brood of vipers, how can you who are evil say anything good? For the mouth speaks what the heart is full of. A good man brings good things out of the good stored up in him, and an evil man brings evil things out of the evil stored up in him. But I tell you that everyone will have to give account on the day of judgment for every empty word they have spoken. For by your words you will be acquitted, and by your words you will be condemned.”

Proverbs 10:20-21 NIV
The tongue of the righteous is choice silver, but the heart of the wicked is of little value. The lips of the righteous nourish many, but fools die for lack of sense.

Proverbs 12:18 NIV
The words of the reckless pierce like swords, but the tongue of the wise brings healing.

Proverbs 4:23 NIV
Above all else, guard your heart, for everything you do flows from it.