The tongue is a “small part of the body” (James 3:5), yet Proverbs 18:21 says it “has the power of life and death.” This holds true whether we’re speaking of spiritual, physical, or emotional “life and death.”
In order to take Proverbs 18:21 literally – that the tongue can cause spiritual, emotional and physical life and death – we do not need to repeatedly tax our imagination. Words create actions; both good and bad. A judge or jury, by simply saying a word, can sentenced a person to life or set them free. Words often save lives: a doctor advises surgery, a weatherman issues a tornado warning, a counselor gives hope to a suicidal person. Conversely, words can also kill: murders are often initiated because of arguments or verbalized hatred. In the sense of causing action, then, the tongue does indeed have the power of life and death.
On a side note my beloved brothers and sisters, please make note the enemy can’t curse you! But irregardless if you fully embrace the contextual admonition in Proverbs 18:21, the enemy clearly understands there is power of life and death in the tongue. So his entire strategy is to get you to curse yourself and others. He accomplishes this by planting negative thoughts in your mind; enticing you to say them out of your own mouth about yourself and others! Go figure…
Here’s the all inclusive bottom line; God made us expressive beings, so we are nearly lost without communication. That is why we have audio recordings and Braille for the blind, sign language for the deaf, and writing for anyone who has something to say from afar. Indeed, speech has enormous implications, especially as a vehicle for sharing the gospel (Romans 10:14). Therefore, we are commanded to control the tongue, to “keep [it] from evil and your lips from speaking lies” (Psalm 34:13). A Christian’s speech should consistently honor the Lord: with the tongue “we praise our Lord and Father, and with it we curse men, who have been made in God’s likeness. Out of the same mouth come praise and cursing. My brothers, this should not be” (James 3:9-10).