Once upon a time, a woman went to an unusual store to buy something for her husband. Only she didn’t quite have enough money to purchase the item. But the store owner was kind, and knew how important this item was to her and her husband. And so, he set up interest-free payments on a monthly schedule so that she could take it home immediately. The woman gave it to her husband on his birthday. It was only a few days later that her husband wound up in the hospital, having been shot in the chest. She rushed to the emergency room to find out how he was doing. They assured her that he was doing fine, and that the damage was mostly bruises. You see, the item she had bought for her husband was a bulletproof vest. He was a police officer. That vest had saved his life. In the same way the breastplate of righteousness saves our lives from the bullets that Satan wants to shoot at us. We should not delay in putting on this vital piece of armor.
The breastplate was a most important piece of armor, second only to that belt that kept your clothes from getting all tangled. However, after you have the truth clearly presented to you, you need something that will protect your heart. That is the very definition of something vital, isn’t it? The word vital means having to do with life itself. The heart is a most important organ in your body. It is essential. Without a heartbeat, a medical doctor will pronounce you dead. And, in this life, there are countless things that will assault your heart, countless things that will compete for your allegiance. As Jesus says, “Where your treasure is, there your heart will be also.” Satan will constantly throw things at you to keep your heart from being in the right place, which is being the throne of Jesus, who then sits on the throne of your heart as King Jesus, Lord of your life. So we can see that it is important. There are two questions that we need to answer in order to know its place in our lives. The first question is this: “How do I put on this breastplate?” The second question is this: “How does it protect me?” Related to this second question is how do we use this breastplate.
So, taking these questions in order, we ask the question, “How do we put on this breastplate?” This is not a small question, since our call to worship from Isaiah tells us that God Himself wears this righteousness as a breastplate. In other words, we are seeking to put on God’s own armor. Any breastplate of righteousness that we put on is cut from the same metal as the breastplate that God wears when He goes to battle against His enemies. Of course, this is all metaphorical language, since the righteousness of God is not something distinct from who God is, whereas a breastplate is something distinct from the person wearing it. Righteousness is God’s obedience to His own law. You know, we often say that God can do anything. That is not true. God cannot sin. He cannot transgress the laws which He Himself made. That would be against His own character. So we say then that God is perfectly righteous.
That raises a most important problem. For we are not righteous. So, the question of how we put on this armor becomes nothing less than the question of the gospel itself. How can we be righteous in our lives? To begin to answer this question, we can say that there are two parts to the righteousness that we can have. First, there is the righteousness outside of ourselves that is reckoned to be ours. That would be the righteousness of Christ. Jesus came to earth, and was perfectly obedient to the law in every respect. The reason He did that was not just to take upon Himself the guilt of our sin. It was also so that we might be able to receive a perfect righteousness that answers to the law in every respect. So, it is in no way our righteousness. It is an “alien” righteousness, as Martin Luther would say. It is outside ourselves. When we come to faith in Christ, that “alien” righteousness becomes ours by God’s declaration. I wish to read to you the entire question and answer 60 from the Heidelberg Catechism, which addresses this very question in a very clear way: “How are you righteous before God?” Answer: Only by true faith in Jesus Christ: that is, although my conscience accuses me, that I have grievously sinned against all the commandments of God, and have never kept any of them, and am still prone always to all evil; yet God, without any merit of mine, of mere grace, grants and imputes to me the perfect satisfaction, righteousness, and holiness of Christ, as if I had never committed nor had any sins, and had myself accomplished all the obedience which Christ has fulfilled for me; if only I accept such benefit with a believing heart.” So, there you have it. It is as if I had done it, but I haven’t. Christ did. But I am reckoned to have done it, because, by faith, I lay hold of Christ’s righteousness. That is the first kind of righteousness which makes up this breastplate. By the way, this is called justification.
The second kind of righteousness that makes up this breastplate is our own righteousness. This is never perfect in this life. And it is something that God works in us. When we come to faith in Christ, not only are we justified by faith, and not by our own works, but the Holy Spirit also comes to live inside of us, and change us. When that happens, then we gradually become more and more righteous over the course of our lives. This process is gradual, and it is not always moving in an upwards direction. However, the trend line is in an upwards direction. This is an important point to remember. We should not become discouraged because there are certain times in our lives when we do not seem to be very righteous at all, and we fall into that same sin time after time after time. Then we come to doubt our salvation. We should not be discouraged. There is a reason why God leaves some sin in our lives to be gradually overcome. If we were perfect already, we would be tempted to take credit for it. Also, we would be tempted to rely on ourselves for our own righteousness, rather than relying on the Holy Spirit. You see, flesh and blood cannot inherit the kingdom of God, as Paul says. So, our own righteousness is always going to be imperfect in this life. That is no reason to stop fighting sin in our lives. It is no reason to give up. On the contrary, we are in a race to the finish line. Sometimes we run, sometimes we walk, sometimes we stumble. But we still keep going to that finish line. And God is waiting there for us to greet us at the finish line. He is not only cheering us on. He is helping us to get there. What a great and good God we serve! This righteousness is called sanctification. The word comes from a Latin root that means “holiness.” Holiness means being separate from the world. So, the process of sanctification means becoming more separate from the world, more like Christ every day. Of course, we do not mean separated from the world, as if we live in our own little enclave and never come into contact with people who are worldly. But it does mean that we do not behave like them because our hearts are different. We have the righteousness of Christ as a breastplate. And we have the righteousness that the Holy Spirit works in us. Those two things radically distinguish us from the world. The world has neither kind of righteousness. That is why the world will have a very rude awakening. So, again, our question has been this: how do we put on this breastplate? The answer is by faith. Again, as Heidelberg Catechism, question 60 says, just in the very beginning, “How are you righteous before God?” The answer starts out by saying “Only by true faith in Jesus Christ.” Faith is the instrument, the tongs, by which we lay hold of Christ’s righteousness. But faith is also the way in which God implants the Holy Spirit in our sanctification. Faith is our lifeline to God. By it God draws us to Himself. He uses our faith to make us more righteous. So faith is the answer to how we put on the breastplate.
The second main question we wanted to answer was this: how does this breastplate protect me? What good does it do? Why should I have it on? Well, Satan is known as the accuser of Christians. He is always accusing us of leaving the faith, or of having bad motives, or of sinning our way out of God’s grace. He accused Job of bad motives, and he did that to God’s face. What is important to know here is not only that our breastplate protects us (since the righteousness of Christ is not something that can be lost, nor is it imperfect), but also that God uses those accusations to defeat Satan’s own purpose. God turns the table on Satan. I would say, then, that the best thing that the breastplate does is to comfort us. For those who trust in Christ, we have protection for our very hearts. We have the breastplate of righteousness. So put it on by faith so that Satan’s accusations will bounce off like a bullet does against a bulletproof vest. He cannot pierce your heart, for your heart is in the hands of God. Indeed, Satan could no more pierce your heart than he could pierce God’s own heart, since your breastplate is of the same metal and manufacture as God’s own armor. So put it on by faith, and see what it will do.