What is the definition of justification?

Les teaches that justification is that judicial act of God whereby He declares the sinner just as if he had never sinned. He connects this to the righteousness of God being unveiled, because when Christ died He completely fulfilled everything a holy God could possibly demand. The veil was rent from top to bottom, opening the very holiest of holies and the presence of God, not just to the high priest on the Day of Atonement but to everybody. Since everything needed has already been accomplished, man's attempt to add his own doing is an embarrassment to God. The justified ones are those declared just, and the sin problem began in Adam, in whom all were included.