Therefore put on the full armor of God, so that when the day of evil comes, you may be able to stand your ground, and after you have done everything, to stand. Stand firm then, with the belt of truth buckled around your waist, with the breastplate of righteousness in place... (Ephesians 6:13-14)
Sometimes during PT we run in our body armor to add weight and make running a little more challenging. Once PT is done, we can drop that heavy armor in the closet. When we are deployed, however, we wear it 24/7 because if lead starts flying we want to have it on. For the believer, our body armor is RIGHTEOUSNESS. Not our own righteousness, but the righteousness of Christ. It's issued to us at spiritual birth. This spiritual flack vest is put on by acknowledging the fact that our good deeds don't cut it. If we begin to think that somehow our good works make us more acceptable to God, the spiritual shrapnel of Satan's accusations begin to wound us. We need Christ to protect us with His holiness. Nothing can penetrate the Righteousness of Christ. Keep your spiritual body armor on.