This article of faith is the very heart of the Gospel and the most important teaching in the Holy Scriptures. To justify means “to be declared righteous” or ‘not guilty’. God’s sure and certain declaration that we are righteous in His eyes is possible only because of our Savior, Jesus Christ. Through His life, Jesus satisfied God’s demand for perfect obedience. Through His sacrificial death, Jesus endured God’s just wrath and atoned for the sins of the world.
In sum:
Our Lutheran churches also teach that people cannot be justified before God by their own strength, merits, or works. People are freely justified for Christ’s sake, through faith when they believe that they are received into favor and that their sins are forgiven for Christ’s sake. By His death, Christ made satisfaction for our sins. God counts this faith for righteousness in His sight (Romans 3:21-26; 4:5).
Praise God for His mercy and grace! The Holy Spirit, through the means of grace, Word and Sacraments, works in us saving faith, which personally receives what Christ has done for us. Our justification before God, therefore, is brought about by the One who lived, suffered, and died for our salvation. We cannot merit God's favor through our obedience; we cannot offer sacrifices to pay for our sins. But what we cannot do for ourselves, Christ has done for us. He is the solid Rock on which God builds His Church. On Him, and Him alone, we stand forgiven.
--Helping people live life with Jesus everyday,