He shall cover thee with his feathers, and under his wings shalt thou trust: his truth shall be thy shield and buckler. ‭‭Psalms‬ ‭91:4‬ ‭KJV‬‬

As we speak God’s truth, we are covered by His truth. Our words are spirit just as Jesus said in John‬ ‭6:63‬, It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life.

Proverbs 8:6-9 (KJV)
6  Hear; for I will speak of excellent things; and the opening of my lips shall be right things.
7  For my mouth shall speak truth; and wickedness is an abomination to my lips.
8  All the words of my mouth are in righteousness; there is nothing froward or perverse in them.
9  They are all plain to him that understandeth, and right to them that find knowledge.