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. Ephesians 6:13
When Roman soldiers went to war, they did not dress normally, but they put on a special suit to shield themselves from arrows, spears and swords of the enemy army. If not, their bodies were unprotected, making it easy to kill them.
Today this armor is spiritual, and the book of Ephesians speaks of it so that we are able to stand against the snares of the evil one. It encourages us to put on: the helmet of salvation, so no dart can enter our minds; the breastplate of righteousness, knowing that our God is righteous and we walk in it; the shield of faith, so we can battle circumstances, having the certainty of what is not seen; the belt of truth, which does not let us lie; the sword that is the Word, for it is two-edged, and a discerner of the thoughts and intents of the heart; and feet shod with the Gospel of peace, to proclaim the victories of the Lord.
If we always wear this armor, there will be no enemy that can take us. Let us clothe from head to toes, for there will be no gap for any of the weapons with which he comes to attack. And, if soldiers are careful in the natural, we must be much more careful, knowing that our fight is not against flesh and blood.
We already know how to protect ourselves for the war we have to fight every day!