As I begin to answer this question, it’s important to note that, from an answerer's point of view, it’s hard to give an accurate answer because of the question’s lack of specificity. Which RCC sources emphasize and explain concupiscence? Which protestant group are you contrasting the RCC view with? These would be necessary in framing a proper question. And yet are lacking.
However, despite the lack of sources and focus, I’ll take a stab and answering your question.
What is concupiscence?
Muller offers up this useful definition:
Concupiscentia: profound desire, particularly in a wrongful sense; specifically, the wrongful desire that is present in the parents during the act of intercourse, which then passes on to the children and which, as an inborn stain, becomes the fomes peccati (q.v), or source of sin, in the succeeding generation. Concupiscence is thus both the privatio iustitae originalis, the privation of original righteousness, and a positive cause of sin.
(Dictionary of Latin and Greek Theological terms. p. 76)
This is a very useful definition. The basic sense of the term is from “cupio” (strongly desire). But, as a technical term in Medieval thought, forms two parts:
- with a strong desire to do evil
- without righteousness.
What’s at stake?
The issue, then, in the Reformation era was this: What effect did the fall into sin have on humanity? How bad was the fall? What effect did it have on people as they were conceived and later on born?
This is a massively important question. For if one concludes that the effect of sin handed down to us is large, it will remove the ability from humans to either earn or help earn their own way into heaven.
The RCC view
The RCC concluded that the will of humans, while damaged, in the fall, is, nevertheless, usable to partner together with God and then earn salvation. Here are some citations which show this thought/teaching:
Bellarmine:
- Bellarmine: Si quis igitur a nobis quaerat, quid proprie sit peccatum originale, respondebimus cum distinctione ad hunc modum: Si peccatum pro actione cum lege pugnante accipiatur, peccatum originale est prima Adami inobedientia.… Si vero peccatum accipiatur pro eo, quod residet in homine post actionem et unde idem homo non peccans, sed peccator nominatur, peccatum originale est carentia doni justitiae originalis, sive habitualis aversio et obliquitas voluntatis. Die Erbsunde in uns sei lediglich privatio justitiae originalis
- Bellarmine: If anyone therefore asks us what original sin is in the proper sense of the term, we will answer by making a distinction in this way: If sin is taken for an action conflicting with the law, original sin is the first disobedience of Adam.… But if sin is taken for that which resides in man after the act and from which the same man is called a sinner although he does not sin, original sin is the lack of the gift of original righteousness, or the habitual aversion and deflection of the will.
Biel:
- Biel: Posse non-renatos per opera poenitentiae impetrare justificationem.
- Biel: The unregenerate are able to obtain justification through works of penance.
Synod of Orange:
- Synod of Orange. Liberum arbitrium per lapsum primi hominis infirmatum atque attenuatum, non extinctum fuisse.—Habet (homo naturalis) enim potentiam remotam et vires imperfectas, et ideo nihil per se potest, sed si perficiatur ea potentia, et vires addantur, poterit praestare.—Quomodo liberum est arbitrium ad utrumlibet ante gratiam, si bonum facere non potest? Respondeo: liberum est, sed ejus libertas quasi est ligata et impedita; solvitur autem et expeditur, cum potentia proxima ad operandum per Dei gratiam praevenientem ei confertur
- Synod of Orange: Through the Fall of the first man the free will was weakened and reduced, not extinguished.—For (natural man) has a remote power and imperfect strength and therefore can do nothing by himself; but if that power is perfected and strength is added, he can do something (good).—How is the will free to do what it pleases before grace (is given), if it cannot do good? I reply: the will is free, but its freedom is so to speak bound and hindered. It is released, however, and expedited when through God's prevenient grace the very power of doing (good) is conferred on it.
While many other sources could be cited, this is enough establish the point: to the RCC, the fall into sin weakened the human will, but did not incapacitate it.
This is a vital point to understand. For, if the will is incapacitated, then it would not be able to cooperate/participate in the RCC salvation structure. Pennance, as a way of helping to earn salvation would be impossible. Indulgences would be impossible. The prayers of the saints for those still here on earth (and invoking their names here on earth too) would be impossible. In effect, the heart and soul of RCC theology would collapse if the fall into sin left more of an impact on the human will.
The view of the Reformers
Here is where specificity is needed. Among the Lutheran (and later on Calvinist) groups, they searched through scripture and found that the fall into sin left a deep and profound dent into the human will. For example, the Lutherans concluded...
- human nature is corrupt (sinful). (cf Gn 6:5; Gn 8:21; Jn 3:5,6; Eph 2:3.)
- such corruption is universal. (1 Kings 8:46; Ps 14:2,3; 143:2; Pr 20:9; Ro 3:9–12,22,23; Ga 3:22.)
- Although original sin is a deep-rooted evil, it is not the substance of man. (cf Jn 1:3 coll 1Ti 4:4;—Ro 7:18; He 12:1.) This last point is important. If the essence/substance of humanity were absolutely destroyed in the fall into sin, then Jesus would have assumed a sinful nature when he was conceived and born.
For a formal statement on the Lutheran view, the Book of Concord is the official document. For Calvinists, cf. the Westminster Confession and Calvin’s institutes.
Notice then the importance of understanding this conclusion and distinction. Both Lutherans and Calvinists, as a result of a thorough study in God’s word, were forced both by scripture and their own consciences to divorce themselves from the RCC process of salvation. For, to their understanding, if the fall into sin has incapacitated us, then God, from the outside, completely on his own, has to do the work of creating faith in us.
The Roman Reaction
The RCC in the council of Trent issued this statement concerning this issue of concupiscence:
- Trid. Sess. V.5: An concupiscentia post baptismum et poenitentiam in renatis reliqua vere et proprie peccatum sit? Hanc concupiscentiam, quam aliquando Apostolus peccatum appellat, sancta Synodus declarat, Ecclesiam Catholicam nunquam intellexisse peccatum appellari quod vere et proprie in renatis peccatum sit, sed quia ex peccato est et ad peccatum inclinat.… Si quis autem contrarium senserit, anathema sit. — In baptismo tollitur formale peccati originalis; ergo reliquiae post baptismum, sc. concupiscentia, non sunt vere peccatum. Nam sublato formali, tollitur res ipsa.
- Trid. Sess. V: (The question is) whether concupiscence which remains in the regenerate after baptism and repentance is truly and properly sin. The holy synod declares that this concupiscence which the Apostle sometimes calls sin the Catholic Church has never understood to be called sin in the sense that it truly and properly is sin in the regenerate, but because it comes from sin and inclines to sin.—If anyone, however, thinks differently, let him be damned.—In baptism the essence of original sin is removed; therefore the remnants after baptism, namely, concupiscence, are not truly sin. For when the essence is removed, the thing itself is removed.
In her official writings, the RCC has officially condemned Lutherans and Calvinists to burn in hell forever (anathema sit) as a result of their teachings.
The Zwinglian option
While not directly related to the reaction at Trent, it is also worthy of note to speak of the followers of Zwingli. Zwingli writes:
- Zwingli: Velimus, nolimus, cogimur admittere, peccatum originale, ut est in filiis Adae, non proprie peccatum esse. Non enim est facinus contra legem. Morbus igitur est proprie et conditio.
- Zwingli: Whether we want to or not, we are forced to admit that original sin, as it is in the sons of Adam, is not sin in the proper sense of the term. For it is not a crime against the law. Therefore in the proper sense of the term it is a disease and condition.
We notice that Ulrich Zwingli’s view of concupiscence is much closer to the Roman Catholic view. And still today, there are many protestant groups that follow a far more Roman Catholic approach to this issue. For example, in the Baptist Faith And Message the SBC speaks about humans as being able to “accept” salvation. This is not the teaching of the initial churches of the Reformation (Lutheran and Reformed). This is far more aligned with a RCC understanding of concupiscence than a Reformation understanding. In Roman Catholicism, one makes use of his will to earn salvation with his hands. In Baptist thought, one makes use of his will to achieve salvation with his heart (choosing, accepting, etc.). In practice, there is much overlap between the RCC and many groupings of protestants (esp. those in the Baptist/Arminian camp).
The importance of the issue
If the question is why concupiscence is such an important matter, then the answer is that salvation itself is at stake. If the fall into sin only hinders and wounds the human will, but does not decapacitate it, then there is room for human hearts or hands to partner together with God to get salvation. If, however, the fall is a thorough fall laying low the human will (but not destroying the substance), then God is the one who has to do all of the work in both redeeming us and creating faith in our hearts to know and trust him. That’s why that word was used so much and fought over so much in the Reformation era.
