I liken this window to be a picture of what 1 John 1:6-10 speaks; the Light of life (Jesus) reveals the truth. And darkness keeps us in a lie. What looks acceptable and even clean to us is exposed to the sun’s (Son’s) rays of Light.

If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth. But if we walk in the Light as He is in the Light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin.
If we say that we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. If we say that we have not sinned, we make Him a liar, and His word is not in us.
Jesus’s work is finished; John 19:30– ours is not and has only begun upon the day we believe.
Our work is to walk in the Light, acknowledge first to ourselves what God has revealed and then confess to Him our sin, and we receive His cleansing. It is straight forward and simple.
Here is where it gets muddied. When what is dark and what is Light cannot be distinguished.
How can this be?
Darkness is sin. When we choose to practice sin, we become deceived and even hardened (against the truth) by it; Heb 3:13, and the Light in us, is dark; Matt 6:23.
We will choose to look through the windows of our soul (and spirit) through our personal discrimination rather than the Light of the Word.
Whenever we hear anyone argue against being a righteous and holy people for God should be a cause for concern as it is contrary to God’s word. Frankly, it insults the spirit of grace that God grants to all who are His. This grace is the same power that raised Christ from the grave and the same power that works in us to will and for God’s good pleasure! Phil 2:13.
May we be diligent in keeping our windows in the Light of Jesus Christ for we will not be ashamed because in Him we receive His cleansing. It is not about being consumed about making sure we do not sin, rather about being militant in keeping ourselves in the Light!