"God does not want to redeem us through our own, but through external, righteousness and wisdom; not through one that comes from us and grows in us, but through one that comes to us from the outside; not through one that originates here on earth, but through one that originates in heaven. Therefore, we must be taught a righteousness that comes completely from the outside and is foreign. And therefore our own righteousness that is born in us must first be plucked up. Thus we read in Ps. 45:10 'Forget your people and your father's house, etc.' Abraham, too, was ordered to leave his father's house in this way (Gen 12:1). Thus we read also in the Song of Solomon (4:8) 'Come from Lebanon, my spouse, and you shall be crowned.' Also, the whole exodus of the people of Israel formerly symbolized that exodus which they interpret as one from faults to virtues. But it would be better to understand it as an exodus from virtues to the grace of Christ, because virtues of that kind are often greater or worse faults the less they are accepted as such and the more powerfully they subordinate to themselves every human emotion at the expense of all other good qualities. Thus the right side of the Jordan was more afraid than the left side. But now Christ wants our whole disposition to be so stripped down that we are not only unafraid of being embarrassed for our faults and also do not delight in the glory and vain joys of our virtues but that we do not feel called upon to glory before men even in that external righteousness that comes to us from Christ. Nor should we be cast down by sufferings and evils which are inflicted on us for His sake. A true Christian must have no glory of his own and must to such an extent be stripped of everything he calls his own that in honor and dishonor he can always remain the same in the knowledge that the honor that has been bestowed on him has been given not to him but to Christ, whose righteousness and gifts are shining in him, and that the dishonor inflicted on him is inflicted both on him and on Christ."
Martin Luther, Lectures on Romans (Luther's Works 25:136-7)