Ephesians 6:16 KJV
 Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked.
As Paul wrote to these familiar words to the church, armor and weaponry would have been something they could easily understand. The entire world understood this picture because the Roman Empire and Roman soldiers were a part of their everyday lives. One of the key aspects that made the Roman military so strong in battle was the equipment they used, and Paul was comparing that equipment to spiritual things that a Christian needed to be strong in the Lord.
In that time period, Romans had various types of shields depending on what type of battle they were going into. They would use smaller, circular shields that one might expect a soldier to use. But they also had very tall and broad shields that were very successfully used in battle in combination with shields of fellow soldiers to protect the front line. The shield Paul here is referring to is a tall and wide shield that would nearly cover the entire body for protection. Roman tactics had many soldiers with these shields standing closely together with shields overlapping in front of and above the front line of soldiers. The shields would provide an impenetrable wall that no spears or arrows could get through. When used efficiently, these shields together made them nearly impossible to defeat.
As Paul, under the inspiration of God, points out, Faith is a spiritual defense against attacks of Satan. But Faith is not just a personal shield. It is a shield that helps to defend those closest to you, and combined faith of many people can make a wall of protection that cannot be easily penetrated. How often does Preacher talk about the prayers of faith that his mom made for him? Her faith was so vital in his life, and our faith can help others as well. Spouses, children, friends, our pastor, our community, and our world all need us to be strong in faith, not just for us, but for them as well. It is not enough for the Pastor alone to have all the faith.
And finally, the shield was useful for another purpose. After a battle, there were undoubtedly those that were injured. The shield could be used as a stretcher of sorts to carry the wounded away. It is difficult to watch others fall prey to Satan’s attacks, but our faith may be the only chance they have at restoration. When someone falls, instead of doing further hurt with negative speech, help to restore them in love and faith.