2 John 1:8

Lest ye lose that which ye have wrought : the Greek reads in the first person, lest we lose, &c. Lest I should have preached to you in vain, and lest both I and you should lose all our former labour. As the old saying hath it, "There is no greater unhappiness than to remember that we once were happy."

But that ye may receive a full reward. That is, if ye take heed to yourselves, and persevere, your perseverance will bring you a full reward. Full, i.e. copious and abundant. For he who falls back, even though he afterwards repent, receives only a half reward, for he loses all the time and the works of the period of his apostasy. The Greek has α̉πολάβωμεν, that we may receive, for the reward of an Apostle and teacher is full when he sees the fruit of his works in his disciples, and when he is honoured and crowned, not only in himself, but in them. As S. Paul says, "What is our hope, or joy, or crown of glory? Ye are our glory and joy."