"Finally, be strong in the Lord and in the strength of his might. Put on the whole armor of God, that you may be able to stand against the schemes of the devil. For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places. 

Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm. Stand therefore, having fastened on the belt of truth, and having put on the breastplate of righteousness, and, as shoes for your feet, having put on the readiness given by the gospel of peace. In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; and take the helmet of salvation, and the sword of the Spirit, which is the word of God."  (Ephesians 6:10-17)

At the end of Paul’s letter to the Ephesians, he exhorts Christians to be strong in the Lord. The reason for this is that he knows that we are in a spiritual battle. The devil and his demons are real, but they do not fight us in a Hollywood manner. They don’t typically show themselves as in the movie The Exorcist. Instead they fight us more subtly. We will see how over the course of the next several weeks. If we are to stand against them, we must put on the armor of God. Therefore, we must have an understanding of the armor.             

The way in which we are to be strong is to “put on the whole armor of God.” Paul is applying a metaphor he used previously when he said to “put on the new self, created after the likeness of God in true righteousness and holiness” (Eph 4:24 ESV). To put on the new self is to put on the armor of God. We cannot put on only part of the armor, but we need the “whole armor of God.” This indicates that we are totally dependent upon God for strength. It is not like God gives us some strength and we provide the rest. No God gives us all the strength we need for the battle.

When Paul calls this the armor of God he is saying that this armor not only comes from God, but that it is also God’s armor. We see God clothed in this armor in various Old Testament passages. Let’s take a look at some passages from Isaiah. In Isaiah 11 we read of the prophecy concerning Jesus Christ. He is the shoot of Jesse that will come. Notice how Isaiah describes him in verses 4-5,  

"but with righteousness he shall judge the poor, and decide with equity for the meek of the earth; and he shall strike the earth with the rod of his mouth, and with the breath of his lips he shall kill the wicked. Righteousness shall be the belt of his waist, and faithfulness the belt of his loins."

In Isaiah 59 we see the prophet describe God himself. He writes of God in verse 17, 

"He put on righteousness as a breastplate, and a helmet of salvation on his head; he put on garments of vengeance for clothing, and wrapped himself in zeal as a cloak."

One more passage in Isaiah 52:6-7. Here we see that it is God himself that preaches the good gospel,    

"Therefore my people shall know my name. Therefore in that day they shall know that it is I who speak; here am I." How beautiful upon the mountains are the feet of him who brings good news, who publishes peace, who brings good news of happiness, who publishes salvation, who says to Zion, 'Your God reigns.'"

The imagery of the Armor of God is drawn from Old Testament descriptions of God and the messiah. We will look at these pieces of armor next week. My point in drawing your attention to it now is in order to see who is wearing this armor. It is God that wears this armor. The metaphor of the armor of God is another way of saying that we take our refuge in God. It is another way of speaking about our union with Christ. In order to put on the armor of God you must have faith in Jesus Christ and be united to him. In Christ we wear God’s armor.