And hateth his brother (kai ton adelpon autou miswn). Sharp contrast between the love just described and hate. The only way to walk in the light ( 1 John 1:7 ) is to have fellowship with God who is light ( 1 John 1:31 John 1:5 ). So the claim to be in the light is nullified by hating a brother. Even until now (ew arti). Up till this moment. In spite of the increasing light and his own boast he is in the dark.