Merriam-Webster defines righteousness as acting in accordance with divine or moral law. Going by this definition, a Breastplate of Righteousness would mean living a law-fulfilling life according to both divine rules and moral ones.
I wore such a breastplate for a few months early in my Christian journey and got skewered halfway to spiritual death before I realized that although I was wearing a Breastplate of Righteousness, it was not the one prescribed by God as part of His armor. That breastplate I had on was based on my own righteousness, not God’s!
A breastplate of our own righteousness is strong to look at, but is inherently weak because it is based largely on our own verdict of ourselves, or the verdict of others, and both are fickle. As long as we judge ourselves (or are judged) favorably, the breastplate we wear appears strong and fills us with confidence. The moment this changes, the breastplate splinters and we become vulnerable to attack from the enemy.
Paul realized this early in his Christian life. In his days as a Pharisee, Paul had it all. He was brought up in Jerusalem as a disciple of Gamaliel and was a very highly respected member of the elite Sanhedrin. He was fanatical about the law, and even among the Pharisees who were renowned for their strict adherence to it, Paul was in a league of his own. He was about as righteous as they came. Yet, when he discovered the righteousness that comes from God, he considered everything else “rubbish.”
More than that, I regard everything as loss because of the surpassing value of knowing Christ Jesus my Lord. For his sake I have suffered the loss of all things, and I regard them as rubbish, in order that I may gain Christ and be found in him, not having a righteousness of my own that comes from the law, but one that comes through faith in Christ, the righteousness from God based on faith. (Philippians 3:8-9)
What made Paul realize that he was foolish in his estimation of own worth was a sudden glimpse that he had of himself through God’s eyes. If we were to examine ourselves through God’s eyes, even for a few minutes, we would undoubtedly come to some equally illuminating conclusions about our own sense of righteousness. The only righteousness that matters is God’s, but what is it and how do we obtain it?
For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God. (2 Corinthians 5:21)
Jesus became sin for us, which he then nailed to the cross with his death, and proceeded to give us eternal life with his resurrection—and the automatic righteousness of God! To obtain it, all we have to do is have faith in Jesus! And then, with this righteousness, we don’t have to worry anymore about whether we are good enough for God or if our past sins will be an obstacle in receiving God’s blessings; we are simply made righteous!
It is sometimes hard for us to comprehend that our sins are all forgiven and that none of our unrighteous deeds are held against us, but it is true. We can go boldly to God as if we had done nothing wrong and know that God will make us right with him simply because we believe and accept the death of Jesus Christ on the cross for our sins. Do take a minute to absorb this because it is a fundamental—and extremely powerful—precept of the Christian faith that not all are aware of!
But the story does not end here. There is double sided protection available in God’s righteousness. Not only does it defend our conscience from all the wounds inflicted by past sin and failures, it keeps us safe from wounds that might be inflicted in future! God’s righteousness imparts something of God in us, something which gives us the power to put sin away. This is His Holy Spirit. To wear the Breastplate of Righteousness with any degree of efficacy, we need to be obedient to the Holy Spirit and keep the power of holiness and righteousness in our life and conduct. Only to the extent that we live in union and fellowship with Christ do we become the righteousness of God!
There is another element of the Breastplate of Righteousness in addition to faith and that is love.
But since we belong to the day, let us be sober, and put on the breastplate of faith and love ... (1 Thessalonians 5:8)
The Breastplate of Righteousness is also a breastplate of faith and love. While faith is the essential element of the breastplate, it is a faith that works only through love. Paul speaks about this in yet another letter, this one to the Galatians.
For in Christ Jesus neither circumcision nor uncircumcision counts for anything; the only thing that counts is faith working through love. (Galatians 5:6)
If we wear our Breastplate of Righteousness without love, like some people do, it leaves open many chinks in the armor. If we are able to coat our breastplate with love, however, we are practically impregnable. Love, as Paul says in his beautiful letter to the Corinthians, always protects. It also never fails. (1 Corinthians 13:7-8)