We are all born spiritual lepers, that is, full of a disease that ravages us, harms, our neighbors, and separates us from God and His heavenly fellowship. Thanks be to God he comes near to us in Christ Jesus that we might call out to Him for mercy and be cleansed.
33 Original sin is like a spiritual poison and leprosy, as Luther says [LW 7:233]. It has poisoned and corrupted the whole human nature. So we cannot show and point out to the eye, human nature by itself or original sin by itself. Nevertheless, there is the corrupt nature, or essence of the corrupt person (body and soul—the person himself) whom God has created. (Original sin dwells in a person. It also corrupts the nature and essence of the entire person.) And there is original sin, which dwells in human nature or essence and corrupts it. They are not one and the same thing. For example, in outward leprosy the body that is leprous and the leprosy on or in the body are not one thing, properly speaking. But a distinction must also be maintained between our nature as created and preserved by God (in which sin is indwelling) and original sin (which dwells in the nature). These two things can, and must, be considered, taught, and believed separately according to Holy Scripture. . . .
39 Here pious Christian hearts justly ought to consider God's unspeakable goodness. God does not immediately cast from Himself this corrupt, perverted, sinful material into hellfire. No, He forms and makes the present human nature from it (which is sadly corrupted by sin) in order that He may cleanse it from all sin, sanctify, and save it by His dear Son.
Condensed from CONCORDIA: THE LUTHERAN CONFESSIONS, copyright 2005,2006 by Concordia Publishing House. Used by permission. All rights reserved. To purchase a copy of CONCORDIA, call 800-325-3040.
Lord grant you faith in His grace alone for your salvation unto eternal life. Amen