It is evident from 1 John 1:6–7 that John’s emphasis on the fact that God is light in whom there is no darkness at all is more than a theological abstraction. On the contrary, his concern is practical and pastoral — he admonishes his readers to ‘walk in the light as he is in the light.’ For John, embracing the gospel message brings us into fellowship with God the Father through and with Jesus Christ and with each other (1 John 1:3). The genuine nature of this fellowship is seen in a walk that reflects and responds to the truth that is revealed in Christ. Once again, we can see a correlation to Paul’s letter to the Ephesians. These calls to walk in the light of the knowledge of Christ are not offered as a means of gaining fellowship with God; rather, it is because of the fellowship that we possess by faith in Christ that Paul exhorts his readers — and us — to walk in the light. Psalm 36:9 says, “For with you is the fountain of life; in your light do we see light.” Both John and Paul make the point of full purity and knowledge in God revealed in Christ, received by believers and reflected in their thoughts and walk.
