This is from Joseph Prince new book Grace Revolution. This is a power explanation of 1 John 1:9. 

In the two instances where we see the word “sins” in 1 John 1:9, it is the Greek noun hamartia (“a missing of the mark”) indicates “a principle or source of action, or an inward element producing acts… A governing principle or power.”  In other words, it refers to the sin principle, or our sinful state on account of Adam’s sin. By using the noun form of this word, John was clearly not referring to our committing of individual acts of sin, or he would have used the verb form, hamartano. 

     In the light of this, can you see how 1 John 1:9 is not talking about confessing our sins every time we sin in thought or in deed?  John was speaking of the need to acknowledge and confess to God that we are sinners because of Adam’s sin, as well as to receive the total forgiveness for all our sins through Jesus’ finished work. How often do we need to do this?  Only once. That’s why 1 John 1:9 is primarily a salvation verse, one that encourages the sinner to acknowledge and confess his sinful state or “sinner hood,” get born again by faith in our Lord Jesus Christ, and have his sinful state through Adam replaced with a new righteous state through Christ. 

The heretical Gnostic doctrine did not subscribe to a belief in man’s sinful state. John was addressing this heresy directly in the first chapter of 1 John and encouraging the Gnostics to confess their sinful state and receive the Lord’s complete forgiveness and total cleansing from all their unrighteousness through His finished work at the cross. 

Powerful lesson!!!