These things write we. This assurance of the divine fellowship is given in order that they may rejoice with the fullness of joy in the glorious hope. This then is the message. The message heard from Christ, now declared, is that God is light. Light represents truth, knowledge and holiness.
Darkness represents ignorance, error, falsehood and sin.
If we say . . . and walk in darkness. To claim a fellowship with him who is Light and to walk in the darkness of error, of ignorance, and of sinfulness are utterly inconsistent. Do not the truth. He who obeys not the truth walks in darkness. But if we walk in the light.