Put on the whole armor of God. The first century world was a world of stories and parables. When Jesus is illustrating the most critical points related to the Kingdom of the Heavens he resorts to short pithy stories and parables rooted in the agrarian culture of the time. When Paul is concluding this letter to the Ephesians he was looking for one, obvious and commonly seen example of what it would mean to be fully equipped as a Christ follower. I can imagine as he thought of what to use that he saw the chain on the end of his arm and the Roman soldier at the other end of the chain. We put on the whole armor of God so that we can stand against the enemy.
Belt of truth -- for the Roman soldier the belt is what holds it all together. The belt holds the breast plate in place, it holds the sword in place as well. We gird ourselves with the truth. Even though the world is in a relativistic age and does not recognize truth in any ultimate sense, the Christ follower holds fast to the historic and essential truth of the Christian faith. One might start with the creed. Or, even simpler, to recognize that the God who created the universe is a good and loving God.
The breastplate of righteousness -- this is body armor and protects the soldier from frontal attacks. The Christ follower is not covered with his/her own righteousness (it is not our own goodness that protects us). Rather, we are covered with the righteousness of Jesus Christ. This is what protects us from the enemy -- not our own strength, not our own power, not our own goodness; but what Christ has done for us.
The shoes are the gospel of peace-- for the soldier footwear and footing were essential for survival. If a soldier lost their footing and fell in a battle situation it was likely that the solider was not going to survive. The Christ follower is encouraged to note that we stand, not on the aggression of our hearts but on the Gospel of peace. If the good news of Jesus Christ does not bring peace, work for peace, and practice peace we have no where to stand.
The shield of faith -- the Roman soldier carried a large triangular shield. These shields were soaked in water and the wood was layered cross grain. The water and cross grain absorbed the flaming arrows fired at you in battle. The wood stopped the arrow and the water quenched the flame. The shield was designed to interlock with other shields so that the army could create "shield walls" on the battle field. A lone soldier had little hope of survival. Standing together there was strength and hope. This shield -- big enough to hide behind -- is faith. Faith is trust and for the Christ follower it is trust in God. We lock our shields together in faith so that we may stand in difficult times and challenge the gates of hell.
The helmet of salvation -- this protected the soldier's head. Arrows and swords, stones and clubs would be coming at your head (kill the head kill the body). This helmet protected you from most assaults. As Christ followers our protection is the assurance that we belong to God and are returning to God. Salvation here also means wholeness -- we are whole and entire in our relationship with Christ and one another.
The sword of the Spirit (the word of God) -- both a defensive and an offensive weapon for the soldier. The sword was broad. For the Christ follower we do not attack the wiles of evil in the world with our our wisdom or intelligence (although it does all come to bear). Instead we stand on the revealed word of God. But be careful here: this is not a "I'm right and you're wrong" kind of word. The word of God speaks of unity and inclusiveness as well as choice and judgement. There is balance in the word and we would be ill equipped if we only focused on one aspect of the word and not the whole gospel.