Scripture frequently employs the imagery of armor as a metaphor for spiritual defense and protection. Old Testament symbolism emphasizes that God himself is the protector of his people. In Genesis 15, God prefaces his reiteration of the Abrahamic covenant with the assurance, "I am your shield, and your very great reward." Thereafter, the shield becomes perhaps the most common symbol of God's steadfast love and protection in the Old Testament. The metaphor is employed twenty-four times. It is a favorite device of David, who invokes this symbolism fifteen times, as in 2 Samuel 22:31, "He [the Lord] is a shield for all who take refuge in him." In Psalm 91:4, David reveals that security is grounded specifically on the absolute faithfulness of God. In light of God's unfailing fidelity, believers are exhorted to trust in the Lord and take refuge behind him as their protective shield (Psalm 115:9-11).
In the New Testament, the imagery of armor is invoked less frequently. Whereas Old Testament symbolism emphasizes the personification of God as shield, the New Testament reveals various aspects of God's redemptive provision as the means by which the believer may lay hold of God's protection. Such symbolism is employed by Paul (Rom 13:12; Eph 6:10-18; 1 Thess 5:8). The most comprehensive and familiar, of course, is Paul's exhortation to the Ephesian believers to "put on the full armor of God." Paul's use of the Greek word panoplia [πανοπλία] in this connection refers to the basic outfit of a Roman soldier of his day. Believers are warned to take up each element of the armor provided because of the reality of opposition in the spiritual realm (Eph 6:12) and because of the imminence of the day of the Lord (Rom 13:12; 1 Thess 5:8). Every Pauline reference to the symbolism of armor is accompanied by the command to "put on" the armor. This injunction implies that believers should consciously appropriate elements of God's redemptive provision needed for every area of vulnerability to spiritual attack.
Ralph E. Enlow, Jr.