What did a Roman soldier carry in his hands when he went into battle?
A Roman soldier carried his weapon in his right hand and his shield in his left hand when he went into battle. Those were the two items that carried the man into battle, and Paul uses that picture to illustrate righteousness in both hands.
Les explains that Paul often used contemporary things to make a point, and here he uses the Roman soldier. The soldier went into battle with his weapon in his right hand and his shield in his left; those two items carried the man into battle. Paul applies the same analogy, but instead of a sword and a shield, the believer has righteousness in both hands—righteousness, righteousness. Les then points to Romans 3:22, where the righteousness of God is by the faith of Jesus Christ unto all and upon all who believe, with no difference between Jew and Gentile, black and white, rich and poor. That righteousness is imputed and covers every believer; it is not only for a few believers.