We need to have help, and we need to have protection. We need to have invisible armor. The examples that Paul gives are pretty simple. Truth is like armor. Truth can overcome evil.
Truth is stronger than any outward form of power.
If you tell the truth, you never need to be afraid of anything else you've done or said. Truth destroys evil. Another kind of armor, is justice . The more you grow up, the more you grow spiritually, the more you become concerned with justice. It's not just playing fair.