1 John 3:6 - Joseph Benson’s Commentary on the Old and New Testaments

Whosoever abideth in union and fellowship with him By loving faith; sinneth not Doth not commit known sin, while he so abideth: whosoever sinneth Transgresseth any known law of God; hath not seen him, neither known him His views and knowledge of him have been so superficial that they deserve not to be mentioned, since they have not conquered his love of sin, and the prevalence of it, and brought him to a holy temper and life. Or he has not attained to, or has not retained, a spiritual, experimental acquaintance and communion with him. For, certainly, when a person sins, or transgresseth any known law of God, the loving eye of his soul is not fixed upon God; neither doth he then experimentally know him, whatever he did in time past. Macknight thinks it probable that “some of the heretical teachers, condemned by the apostle in this epistle, to make their disciples believe that their opinions were derived from Christ, boasted their having seen and conversed with him during his ministry on earth, consequently that they knew his doctrine perfectly. But the apostle assured his children that, if these teachers, who avowedly continued in sin, had ever seen or conversed with Christ, they had utterly mistaken both his character and his doctrine.”