The Lord is our righteousness.Jeremiah 23:6
It will always give a Christian the greatest calm, quiet, ease, and peace to think of the perfect righteousness of Christ.
How often are the saints of God downcast and sad! I do not think they ought to be. I do not think they would be if they could always see their perfection in Christ. There are some who are always talking about corruption and the depravity of the heart and the innate evil of the soul. This is quite true, but why not go a little further and remember that we are perfect in Christ Jesus.
It is no wonder that those who are dwelling upon their own corruption should wear such downcast looks; but surely if we call to mind "Christ Jesus, whom God made . . . our righteousness,"1 we shall be of good cheer. What though distresses afflict me, though Satan assault me, though there may be many things to be experienced before I get to heaven, those are done for me in the covenant of divine grace; there is nothing wanting in my Lord--Christ has done it all. On the cross He said, "It is finished!" and if it be finished, then am I complete in Him and can rejoice with joy unspeakable and full of glory, "not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith."2
You will not find on this side of heaven a holier people than those who receive into their hearts the doctrine of Christ's righteousness. When the believer says, "I live on Christ alone; I rest on Him solely for salvation; and I believe that, however unworthy, I am still saved in Jesus," then there rises up as a motive of gratitude this thought: "Shall I not live to Christ? Shall I not love Him and serve Him, seeing that I am saved by His merits?" "The love of Christ controls us,"3 "that those who live might no longer live for themselves but for him who for their sake died and was raised."4 If saved by imputed righteousness, we shall greatly value imparted righteousness.
1) 1 Corinthians 1:30
2) Philippians 3:9
3) 2 Corinthians 5:14
4) 2 Corinthians 5:15