{Of God} (ek tou theou). Even human love comes from God, "a
reflection of something in the Divine nature itself" (Brooke).
John repeats the old commandment of  2:7f . Persistence in loving
(present tense agap(936d)en indicative and agap(936e) participle) is
proof that one "has been begotten of God" (ek tou theou
gegenn(8874)ai as in  2:29 ) and is acquainted with God. Otherwise
mere claim to loving God accompanied by hating one's brother is a
lie ( 2:9-11 ).