Isaiah 59:17 He put on righteousness as his breastplate, and the helmet of salvation on his head; he put on the garments of vengeance and wrapped himself in zeal as in a cloak.
In these words we don’t have a description of man putting on the right stuff to go to war, but of The Lord doing so to fight evil.
When Christ comes forward to defend us. He does not come forward as a simple man but as a warrior, ready to fight for everything and against anything.
God is our protector and our shield, He has also given us all we need to know in order to fight with Him to bring people to know more of Him.