Commentaries:
The Word came as a man to die for the forgiveness of our sins (hamartia) without regard to classification! Hamartia is the general word used throughout the New Testament to describe sins of all kinds; it means "to miss the mark" or "to fail to reach a standard." Thus, John is saying that Christ's sacrifice covers all transgressions of law, whether or not we consider them to be physical or spiritual in nature.
Richard T. Ritenbaugh
Sin Is Spiritual!