Footnotes:

1. 1:1–4 There is a striking parallel to the prologue of the gospel of John (Jn 1:1–18), but the emphasis here is not on the preexistent Word but rather on the apostles’ witness to the incarnation of life by their experience of the historical Jesus. He is the Word of life (1 Jn 1:1; cf. Jn 1:4), the eternal life that was with the Father and was made visible (1 Jn 1:2; cf. Jn 1:14), and was heard, seen, looked upon, and touched by the apostles. The purpose of their teaching is to share that life, called fellowship…with the Father and with his Son, Jesus Christ, with those who receive their witness (1 Jn 1:3; Jn 1:14, 16).
2. 1:5–7 Light is to be understood here as truth and goodness; darkness here is error and depravity (cf. Jn 3:19–21; 17:17; Eph 5:8). To walk in light or darkness is to live according to truth or error, not merely intellectual but moral as well. Fellowship with God and with one another consists in a life according to the truth as found in God and in Christ.
3. 1:8–10 Denial of the condition of sin is self-deception and even contradictory of divine revelation; there is also the continual possibility of sin’s recurrence. Forgiveness and deliverance from sin through Christ are assured through acknowledgment of them and repentance.