Preserving the natural beauty of the Appalachian Trail is sometimes summarized in the phrase "Leave No Trace". Because the trail is a place of natural beauty, "Leave No Trace" means leaving it as you find it, or if necessary, cleaning up after those who have not.
Humans were created to enjoy unbroken fellowship with their Creator. Sin pervasively pollutes the human heart and turns it against the Creator. Rather than a purely unbroken relationship we read descriptions in the Bible of the human heart like these:
"For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened."
"And since they did not see fit to acknowledge God, God gave them up to a debased mind to do what ought not to be done. They were filled with all manner of unrighteousness, evil, covetousness, malice. They are full of envy, murder, strife, deceit, maliciousness. They are gossips, slanderers, haters of God, insolent, haughty, boastful, inventors of evil, disobedient to parents, foolish, faithless, heartless, ruthless. Though they know God's righteous decree that those who practice such things deserve to die, they not only do them but give approval to those who practice them". (Romans 8:21, 28-32"
How then, could someone in such a condition be restored to a relationship with God, fully cleansed, no trace of their former pollution?
And you, who once were alienated and hostile in mind, doing evil deeds, he has now reconciled in his body of flesh by his death, in order to present you holy and blameless and above reproach before him (Colossians 1:21-22)
The death of Christ completely removes the pollution of sin from those who put their faith in him for forgiveness so they will, without a trace, be holy and blameless before him.