As Dwight Edwards, author of Revolution Within suggests,
Costume jewelry is essentially worthless metal covered with an attractive coating. So many believers see themselves in that way - sinners through and through, yet covered by the blood of Christ...
Tarnished silver is a much truer image of who we are after conversion.
In "good and noble heart" vernacular, the Christian's heart or true tendency is pure and untainted now, the old diseased heart having been removed and replaced by a completely radiant heart containing no trace elements of sin.
That noble heart may be surrounded by a tarnished layer called, "the flesh" - sinful residual programming leftover even after our old heart was removed; but that tarnish does not penetrate to the level of the new heart. Why? Because your new heart [unblemished silver] is no longer compatible with sin [tarnish]. In fact, your heart propels sin away from it. The unfiltered radiant wattage of your new heart dispels the darkness of the flesh. ["Light shines in the darkness and the darkness cannot overcome it, right?]
Video: "THE PRONE TO WANDER MYTH."