Paul's message in today's epistle lesson is not finger pointing at them, but a warning for us. "Therefore let anyone who thinks that he stands take heed lest he fall. No temptation has overtaken you that is not common to man." We believers are no better of ourselves than unbelievers. So we best not take pride in our piety for that is unbelief.
First, it is true that Christians should regard and recognize the actual transgression of God's commandments as sin; but sin is also that horrible, dreadful hereditary sickness by which the entire human nature is corrupted. This should above all things be regarded and recognized as sin indeed. Yes, it is the chief sin, which is a root and fountainhead of all actual sins. By Dr. Luther it is called a "nature sin" or "person sin." He says this to show that, even if a person would not think, speak, or do anything evil (which, however, is impossible in this life, since the fall of our first parents), his nature and person are nevertheless sinful. Before God they are thoroughly and utterly infected and corrupted by original sin, as by a spiritual leprosy. Because of this corruption and because of the fall of the first man, the human nature or person is accused or condemned by God's Law. So we are by nature the children of wrath, death, and damnation, unless we are delivered from them by Christ's merit.
Second, the following is also clear and true, as Article XIX of the Augsburg Confession teaches: God is not a creator, author, or cause of sin. By the instigation of the devil through one man, sin (which is the devil's work) has entered the world (Romans 5:12; 1 John 3:7). Even today, in this corruption, God does not create and make sin in us. Original sin is multiplied from sinful seed, through fleshly conception and birth from father and mother [Psalm 51:5]. God at the present day still creates and makes the human nature in people.
Third, reason doesn't know and understand what this hereditary evil is [Psalm 19:12]. As the Smalcald Articles say, it must be learned and believed from the revelation of Scripture.
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