The testimony of the apostle concerning the reality of the person and doctrine of Christ; and the end for which he bears this testimony, Jo1 1:1-4. God is light, and none can have fellowship with him who do not walk in the light; those who walk in the light are cleansed from all unrighteousness by the blood of Christ, Jo1 1:5-7. No man can say that he has not sinned; but God is faithful and just to cleanse from all unrighteousness them who confess their sins, Jo1 1:8-10.