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.
"Light" again suggests purity of life in contrasted with the darkness of sin. The persons under consideration are those who are characteristically holy in life. They may step aside in a moment of weakness, but the general course of life is one toward holy living. Habitual walking implies effort, activity, and progress. Those walking in the light of holiness put forth a definite effort to do so; they are active and each day they progressively get better.