The whole plan of the way of salvation is for this end: to glorify the free grace of God. God had it on His heart from all of eternity to glorify this attribute; and therefore it is, that the device of saving sinners by Christ was conceived. The greatness of divine grace appears very much in this: that God by Christ saves the greatest offenders. The greater the guilt of any sinner is the more glorious and wonderful is the grace manifested in his pardon:
"Where sin abounded, grace did much more abound." (Romans 5:20)... The Redeemer is glorified, in that He proves sufficient to redeem those who are exceeding sinful in that His blood proves sufficient to wash away the greatest guilt, in that He is able to save to the uttermost, and in that He redeems even from the greatest misery.
From "Great Guilt No Obstacle to the Pardon of the Returning Sinner" in the The Works of Johnathan Edwards, Vol. 2, reprinted by the Banner of Truth Trust.