“If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth.”
This verse is the first of 3 false claims of spirituality (1:6,8,10). All these claims to spirituality are irreconcilable with the God whose character is pure, unadulterated light. John contrasts each claim against the truth.
If we say that we have fellowship with Him,
“Fellowship” means to share with. We cannot commune with God in fellowship while living in darkness.
and walk in darkness,
If we allow unconfessed sin to lounge in our souls, we cannot fellowship with God because sin and God are antagonistic to each other. If we deny that sin breaks fellowship with God, we undermine the idea unadulterated flawlessness in God.
The word “walk” means to walk around as a pattern of life. The person who walks in darkness is in a condition of unconfessed sin. He is out of phase with the character of God (“light”). He does not resolve Himself to the absoluteness of God in his daily walk because he continues with unresolved sin in his life.
When we deny the incompatibility of God with sin, we enter self-evident self-deception. Any claim contrary to absolute perfection in God is a falsehood.
and do not practice the truth
It is one thing to believe truth but it is another to do truth. In biblical Christianity, truth is not only thinking and believing but also doing or acting. We must follow truth as well as believe it. Spirituality is impossible without showing itself in morality. Truth is more than creed or doctrine because genuine truth always affects our comportment.
Truth always illuminates the soul. Darkness is the absence of light. Wherever there is no light, there is darkness. Truth resides in the translucent atmosphere where we can see our impurities against the absolute character of God.
We cannot fellowship with a God of absolute perfection without confessing our sins.
Those who claim to fellowship with God but continue in sin without confessing their sin, just kid themselves. They are not in fellowship.
A crucial element to the Christian life is the recognition and acknowledgement of our sin. If we do not confess our sin, we walk in darkness. We reserve a dark side to our soul. Darkness is the absence of life. Walking in the light means that we are open to God. We are not afraid to expose any aspect of our lives to Him.
God cannot fellowship with us while we have unconfessed sin in our lives otherwise that would involve God in our sin. The person who rides in a getaway car from a bank robbery is just as guilty as the men who robbed the bank. God always is true to His integrity and honesty.