Often when ministers talk about the "Armor of God" they say there is nothing covering the back which is incorrect. I have a little experience with martial combat and ancient weaponry & armor. When the Apostle Paul was describing the armor he knew it covered both front & back, but the focus of combat is on what is in front of you because your back is supposed to be covered. He was comparing the "armor of God" to the armor of the Roman soldier of that day and the tactics of the Roman military. In a Roman military formation they were trained to cover each other as they progressed forward.
They rarely retreated except to gain a tactical advantage over the enemy or unless it was absolutely necessary in order to regroup. If one ever has to retreat to regroup it would be a shame for their back to be exposed to the enemy as they did, or for them to go forward in a battle and the enemy sneak behind or surround them and they're uncovered except for in the front. It sounds good when preachers say it but it's wrong and wouldn't make any practical sense to a combat or military tactician to wear armor that leaves their backside exposed.
"Melee combat" or "hand to hand" combat is chaotic, and once engaged in such combat you must be confident that you are covered on all sides so you can fight without fear of taking a knife in the back or unwittingly being the victim of "friendly fire" by one of your own. "Friendly fire" happens due to a lack of discernment on the spiritual side just like it stems from a lack of discernment on the natural side. Notice below in Ephesians 6:11, Paul says put on the "whole armour". It's not truly "whole" if it only covers "half". God covers us on all sides. ~ I.J. West
EPHESIANS 6:11-18; "Put on the whole armour of God, that ye may be able to stand against the wiles of the devil. 12) For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. 13) Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. 14) Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness; 15) And your feet shod with the preparation of the gospel of peace; 16) Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. 17) And take the helmet of salvation, and the sword of the Spirit, which is the word of God: 18) Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints".