Bucer’s entire theology of justification is that of double justification. Everywhere he speaks of imputed righteous, he always follows directly with inherent righteousness. I will quote a few examples.
Bucer penned the statement on justification at the Colloquy of Regensburg. I have pieced it together through two secondary sources. He writes:
The movement wrought by the Holy Spirit whereby, truly repenting of their old life, men are turned to God and truly apprehend his mercy promised in Christ, so that now they truly believe that they have received forgiveness of sins and reconciliation through the merit of Christ by the free gift of God’s goodness, and they cry out to God, ‘Abba, Father’: but this happens to no one unless there is also at the same time infused into him that love which heals the will… Therefore living faith is that which apprehends God’s mercy in Christ and believes that the righteousness of Christ is freely imputed to oneself, and at the same time receives the promise of the Holy Spirit and also love… But it remains true that we are justified, that is, accepted and reconciled to God by this faith in so far as it apprehends God’s mercy and the righteousness which is imputed to us on account of Christ and his merit, not on account of the worth or perfection of the righteousness which is imparted to us in Christ.
quoted in David F. Wright “Martin Bucer 1491-1551: Ecumenical Theologian,” in Common Places of Martin Bucer trans. and edited by D. F. Wright, 43
We think that in this begun righteousness is really a true and living righteousness, and a noble excellent gift of God; and that the new life in Christ consists in this righteousness, and that all the saints are also righteous by this righteousness, both before God and before men, ‘and that on account thereof the saints are also justified by a justification of works,’ that is, are approved, commended and rewarded by God.
quoted in Herman Witsius, The Economy of the Covenants Between God and Man Book III. Chap. VIII. 26
In his Common Places, Bucer has this to say:
So in treating of our restoration, Paul intimates in close connection issuing from our very justification before God- provided conviction of it is ours- the immediate presence in believers of the Spirit, the fashioner of all the righteousness we are to display in our lives. Hence he never uses the word ‘justify’ in this way without appearing to speak no less of this imparting of true righteousness than of the round and head of our entire salvation, the forgiveness of sins. In chapter 3 (verse 25) after saying that righteousness is revealed in the era of the unveiling of the gospel, that is to say, is so clearly manifested in the lives of believers that the world now acknowledges these alone to be capable of true righteousness, and after saying secondly, that Christ came to introduce to the world an endeixis, a demonstration of divine righteousness unmistakable to all, he then added, ‘that God himself might be righteous, and the justifier of him who has faith in Jesus Christ’. Here without a doubt he includes at the same time in the word ‘justify’ that righteousness which God produces by his Spirit in those who believe in Christ, and which he intends to be his attestation to the effect that he has now forgiven their sins and counts them among those he resolved to justify, that is, to count among the righteous not only by pardoning their sin but also by conforming them to the image of his Son. The apostle always speaks about our justification in this fashion, never failing to comprehend the summit of our salvation, for which he prayed for the Philippians as follows: “It is my prayer that your love may abound more and more in knowledge and all aesthesis (that is, a quality of discernment) whereby you may be able to approve with certainty what is excellent, and to this end, that you may be pure and give offence to no one, thus being equipped for the day of Christ, and filled with the fruits of righteousness which are produced through Jesus Christ to the glory and praise of God.’
Consequently, since Paul is accustomed to speaking in this way, denoting by the word ‘justification’ first of course the remission of sins, yet at the same time always indicating in addition that imparting of righteousness which God proceeds to work in us by the Spirit, the same Spirit by whom he grants us assurance of the pardon of our sins and of his goodwill towards us, and whom he has established the seal (sphragis) of that pardon- because, I say, Paul customarily speaks in these terms, the majority of the holy Fathers, bearing in mind no doubt the more visible aspect of justification, have taken dikaiousthai, to be justified, in the sense of ‘to be made righteous..
It goes without saying that however great a degree of righteousness the Spirit of Christ might effect in us when we believe, it will none the less be sufficient to merit our being regarded as righteous in God’s sight, for we remain unprofitable servants even when we have fulfilled all his bidding. It was with this in mind that Philip Melanchthon in his highly erudite and devout Commentary on this Epistle rightly condemns those who want to make “We are justified by faith’ mean, “Faith is the source or cause that produces other virtues for whose sake we are pronounced righteous’, or ‘Faith itself is in us a virtue, deserving of God’s approval.’ And he subjoins these godly words: ‘“We are justified by faith” should be transposed in this sentence: “We are reckoned rightoues by mercy” Similarly, “we are justified by faith alone” means, “We are pronounced righteous by trusting in mercy alone”’- so it is only for us to add, ‘as we are given the assurance that we are so pronounced, and thus know by experience this merciful favour of God’. Surely no godly soul can doubt for a moment that it is through God’s mercy alone and for the sake of Christ’s merit alone that we are justified, pronounced righteous before God, and not because of anything in us at all, however many works of holiness, however genuine our fruits of the Spirit. For who is ignorant of the Scripture, ‘Enter not into judgment with thy servant, for no man living will be justified before thee’? And in Isaiah, ‘In the Lord shall all the seed of Israel be justified and praised’.
Bucer notes that sanctification is sometimes included in Paul’s use of justification and this is how many of the Patristics used the term. Bucer does not reject this, but simply adds the concept of imputed righteousness as a foundation for sanctification to rest upon.