Paul taught about the armor of righteousness, 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. Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness; And your feet shod with the preparation of the gospel of peace; Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. And take the helmet of salvation, and the sword of the Spirit, which is the word of God (Eph 6:13-17). See also DC 27:15-18).
The "armor of righteousness" is thought of as a New Testament doctrine even though Isaiah hints at it in Isaiah 59:17. Here we see another instance in which the language and doctrine of the Book of Mormon more closely resembles the New Testament than its contemporary, the Old Testament. This is not an anachronism because a careful study of the Old Testament reveals that "New Testament" ideas were known to the prophets, like Abraham, Isaiah, Moses, Elijah, etc., but the plain and precious truths were not described in plain and precious ways because the Jews preferred to have a riddle. But behold, the Jews were a stiffnecked people; and they despised the words of plainness, and killed the prophets, and sought for things that they could not understand. Wherefore, because of their blindness, which blindness came by looking beyond the mark, they must needs fall; for God hath taken away his plainness from them, and delivered unto them many things which they cannot understand, because they desired it. And because they desired it God hath done it, that they may stumble. (Jacob 4:14)