A confessing life and forgiveness - I John 1:9

I read all the commentaries, heard a dozen sermons, and still confession and forgiveness in 1 John 1:9 remained a mystery.

Why do believers need to confess if they have already have been forgiven? 

9 If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.

So if we don't confess are we not forgiven? Is our redemption as believers based on our confession?  

I think the answer is found in the Greek tenses. I admit I don't have a perfect understanding of the Greek language but it paints a pretty clear, beautiful picture in simply highlighting the use of tenses.

Confession is present active, signifing a continual state. "If you are living a life of confession"...

then

He is (present, continuous) faithful and just to forgive us our sins and to be cleansing us (present, continuous) from all unrighteousness.

Forgive is aroist, active, it's a completed act like a snapshot, simple, completed.

If you are confessing your sins he is faithful and just to have forgiven our sins and to be cleansing us from all unrighteousness. - Joel Version

 

 Like Luther's first theses that states that Christ's call to repentance is a call to a life of repentance, so the call to confession is a call to a life of confession. Confession reaches back and grabs the completed sacrifice of Christ on our behalf, affirms God's forgiveness that has already been applied to your life and continues to transform us today into the image of his Son. 

Without confession we stay stuck in our sin. Confession is the recognition that we are not yet as we will be when we see him face to face.