Death and life are in the power of the tongue; those who love it will eat its fruit.
Proverbs 18:21 (CEB)

And the tongue is a flame of fire. It is full of wickedness, and poisons every part of the body. And the tongue is set on fire by hell itself and can turn our whole lives into a blazing flame of destruction and disaster.
James 3:6 (TLB)

A gentle tongue is a tree of life, but a sinful tongue crushes the spirit.
Proverbs 15:4 (NLV)

Those who control their tongue will have a long life; opening your mouth can ruin everything.
Proverbs 13:3 (NLT)

Let the words of my mouth and the thoughts of my heart be pleasing in Your Eyes, O Lord my Rock and The One Who saves me.
Psalm 19:14 (NLV)