“ Behold, the days are coming,” says the LORD, “ That I will raise to David a Branch of righteousness; A King shall reign and prosper, And execute judgment and righteousness in the earth. In His days Judah will be saved, And Israel will dwell safely; Now this is His name by which He will be called: THE LORD OUR RIGHTEOUSNESS. Jeremiah 23:5-6 (NKJV)
The Name Jehovah-Tsidkenu is first used in Jeremiah 23:6. On our own we are not capable of being right with God. This is the verse where God reveals that He will be our Righteousness. Being born into sin, man is not able to live in complete obedience to God's law. We are slaves of sin, our hearts are evil, focused only on getting and doing things our own way.
“ The heart is deceitful above all things, And desperately wicked; Who can know it? Jeremiah 17:9 (NKJV)
If we are to be right with God, we need a new heart.
I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh. 27 And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws. Ezekiel 36:26-27 (NIV)
Jesus is the Branch of Righteousness referred to in Jeremiah 23:5. Jesus is Jehovah-Tsidkenu. He died to take the punishment for our sins but that is not where it ended. The forgiveness of sin was accomplished with every animal sacrifice prescribed by the law. It was not the Perfect sacrifice because it only accomplished forgiveness until the next sin was committed and then another sacrifice was necessary. What that sacrifice did not accomplish was to make us righteous. It did not change the heart.
For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him. 2 Corinthians 5:21 (NKJV)
On our own we cannot become righteous. That could only be accomplished at the Cross for those who place their faith in Jesus Christ (Jehovah-Tsidkenu) and His power to save. When we place our faith in Christ, we are exchanging our bondage of slavery to sin for a willing slavery of obedience to Christ. This willing exchange is a result of the new heart we are given to be obedient to the Holy Spirit that now lives inside of us.
Don't you know that when you offer yourselves to someone to obey him as slaves, you are slaves to the one whom you obey—whether you are slaves to sin, which leads to death, or to obedience, which leads to righteousness? But thanks be to God that, though you used to be slaves to sin, you wholeheartedly obeyed the form of teaching to which you were entrusted. You have been set free from sin and have become slaves to righteousness. Romans 6:16-18 (NIV)

"A girl needs to be so lost in God, that the guy is going to have to seek HIM to find her!" ...Maya Angelou