Man has a sin problem. Man has a righteousness problem in that we don't have it. This poses a serious problem because one day we will stand before the Creator of the universe and we will be judged by God for our life that He has given us.
God's demand for entrance into His perfect Kingdom is perfect righteousness. Not one single person who has ever lived except for the Lord Jesus Christ has possessed righteousness on their own. This means that mankind not only doesn't possess righteousness but they can't produce it either inherently or over any period of time.
If it were not for the grace and mercy of God Almighty, the population of hell would be 100% of the entirety of mankind. Our only hope is to find a way to be able to stand justified before a perfectly righteous and holy God. We need to find a way to be able to stand just and right before God.
Thankfully, we can find our right standing and we can find our justification in the person of Jesus Christ. He is our justification! He is our Savior! He is our righteousness. This point of theology is seen in sharp contrast to that which other religions teach. For instance, the Roman Catholic church will state that salvation is by grace alone but they mean that the initial part of salvation is by grace alone. They see justification as something that must be maintained or kept up by those who place their faith in Christ. So, for the Roman Catholic, justification in Christ, while it may be necessary is not fully sufficient or complete because it will always require something to go along with it.
The problem with this thinking is there is no assurance or true hope for any believer that can't fully trust that the grace of God has completely and fully saved them. Take for example the following commentary on the subject of justification in regards to the differences between Protestants and Roman Catholics by James White:
"One of the fundamental differences between the Roman Catholic doctrine and the Protestant doctrine is simply this: the righteousness by which we stand before God, according to the Protestant, is the righteousness of Jesus Christ alone. No one will ever stand before God clothed in the righteousness of Christ, Mary, the saints, and himself. The righteousness of Christ is the actual and real possession of the believer. This is the righteousness a Christian pleads before the judgment throne of God. Christ is our Substitute. Our sins are imputed to Him; His righteousness is imputed to us. Christ does not simply merit for us grace so that we can then do good works to earn our way to heaven; by God's grace Christ's righteousness becomes ours, and we have eternal life because of Christ's righteousness, not because of our own."
Dr. White does an excellent job of drawing the contrast between Protestants and Roman Catholics as it pertains to the issue of justification. As he states in the above quote from his book, "This is the righteousness a Christian pleads before the judgment throne of God." This is key because every single person who has ever been created will stand before God one day. We will either stand before God condemned under our own sin or we will stand before Him justified and righteous.
If we aim to stand before God and plead our own righteousness to the Almighty, then we will be eternally condemned to a real place called hell because there is no righteousness in human flesh. There is only righteousness in God. In salvation, we are justified and we have the very righteousness of God imputed to our account. As Dr. White points out, Christ takes on our sin and we take on His righteousness.
So, my friends, I aim to stand before God and not plead my own righteousness but I aim to stand before God and plead the very righteousness of Christ! He is my Substitute! He is my Savior! He is my righteousness! I stand perfectly righteous and justified based on the shed blood of Christ on the cross of Calvary.
Thanks to the death, burial, and resurrection of Christ Jesus we have eternal life, we have power over sin, and we have a standing before God that has been purchased for us by Christ's own blood.
I plead Christ! I plead the righteousness I have in Him! I have repented of my sin and have placed my faith, my belief, and my trust for salvation in the 2nd person of the Holy Trinity; Jesus Christ, the Son of the Living God.