Ephesians 6:13
Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand.

Everyone needs protection, from the smallest newborn to the wealthiest person in the world.
You need protection because there is always someone wanting to steal from you, exploit you, or destroy you.
That is actually a good description of what the devil wants to do to you.
The army, police, a big Doberman, or Smith & Wesson cannot protect you from the devil.
God gives the only total protection against the wiles of the adversary.
A belt of truth. A belt helps keep your pants up. If you’re too busy pulling your pants up all the time you cannot be effective at anything.

The breastplate of righteousness. A breastplate is like a modern bullet proof vest or Kevlar. Above all, it protects your heart (and other organs) from damage.

Shoes of the Gospel of peace. Shoes protect your feet from the things of the world. Briers, pebbles, puddles, or hot pavement. Shoes are a type of foundation for you to stand on.

The shield of faith. A shield protects you by deflecting or stopping projectiles aimed at harming you.

The helmet of salvation. A helmet protects your mind.

And the sword of the Spirit. A sword is a personal weapon that is not used at a distance, like a bow/arrow, spear, or javelin. You will look at someone face-to-face when using a sword.

Ephesians 6:14-17 Stand therefore, having girded your waist with truth, having put on the breastplate of righteousness, and having shod your feet with the preparation of the gospel of peace; above all, taking the shield of faith with which you will be able to quench all the fiery darts of the wicked one. And take the helmet of salvation, and the sword of the Spirit, which is the word of God;