Walking in love takes a continual giving of oneself. That means we have to reach out to others as Christ reached out to us. You cannot be a child of light and have darkness working in your soul.
Darkness represents sin.
But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin. If you are in sin, you are in darkness and you are spiritually blind. That is the reason there are so many different religions in the world. There is a religion that will accommodate those who are spiritually blind. If you are living in sin, you are under condemnation.