These words should not daunt us but rather teach us what we are to aim at. Who can say that they have already arrived at perfect love, but every Christian can say that he has begun to love with genuine love.
He who fears still has a faltering love, a love that is not yet purified to perfection. John does not deny that this may occur – that a man may have love and fear at the same time – but it is an unnatural mixture and indicates the weakness of his faith as well as the imperfection of love. Such a man needs to understand the true basis of his standing with God and see that every cause for fear has been removed and strive towards the goal of perfect love.
Certainly there is a form of fear which we call reverence, which is quite consistent with love, but that is not the kind of fear that John means here. Reverence does not expect punishment from God, and is not tormented by the anticipation of his wrath; it approaches him aware of his greatness but confident of his favour.