“If we claim to have fellowship with him and yet walk in the darkness, we lie and do not live out the truth. But if we walk in the light, as he is in the light, we have fellowship with one another …” 1 John 1:6-7
To “walk in the light” is the same as “walking in God’s commands” – the expression we find in the Old Testament. Walking is a metaphor for the way we live. It doesn’t imply perfect obedience but a heart’s desire to live in a way that pleases God. The alternative is to stumble in darkness.