Jude 1:21

21.Keep yourselves in the love of God. He has made love as it were the guardian and the ruler of our life; not that he might set it in opposition to the grace of God, but that it is the right course of our calling, when we make progress in love. But as many things entice us to apostasy, so that it is difficult to keep us faithful to God to the end, he calls the attention of the faithful to the last day. For the hope of that alone ought to sustain us, so that we may at no time despond; otherwise we must necessarily fail every moment.

But it ought to be noticed that he would not have us to hope for eternal life, except through the mercy of Christ: for he will in such a manner be our judge, as to have no other rule in judging us than that gratuitous benefit of redemption obtained by himself.