Of God (εκ του θεου). Even human love comes from God, "a reflection of something in the Divine nature itself" (Brooke). John repeats the old commandment Rev 1. John 2:7. Persistence in loving (present tense αγαπωμεν indicative and αγαπων participle) is proof that one "has been begotten of God" (εκ του θεου γεγεννητα as in 1. John 2:29) and is acquainted with God. Otherwise mere claim to loving God accompanied by hating one's brother is a lie (1. John 2:9-11).