In baptism, we know that the old man dies (as mentioned by St. Paul in Romans 6), and we rise with Christ. What exactly dies (or what is the old man composed of)? Does the soul or spirit or body of the old man die, or is it just the old nature? What is the relationship between the old nature/man and the soul, spirit, and body of man?
Original Sin is forgiven and the old nature of man is renewed in the Holy Mystery of Baptism. It is figuratively putting on the new garment (new nature). Confession is the washing away of our sins, i.e., the stains on the new garment.
When Adam sinned, his soul, body, and spirit became corrupted (old nature). All of us are born with the original sin as well as the corruption of our nature since we were in Adam when he sinned. In the Holy Mystery of Baptism, we (body, soul, and spirit) participate truly in the death and burial of Christ in a mystical way and then we (body, soul, and spirit) rise again without the corruption as new creation in the Lord Jesus Christ.