While I think Zacharias Ursinus’ thinking would be profitable to consider, I am not recording his reflections in order for readers to come to agreement with his position as a whole. Rather, my interest is twofold. First, I think the way the Heidelberg Catechisms is used as a “proof” of the pedigree of the doctrine of the imputation of the active obedience of Christ to believers is sometimes irresponsible. Second, I think the rhetoric used to describe the importance of the doctrine of the imputation of the active obedience of Christ has sometimes also reached irresponsible levels. Was Zacharias Ursinus a defender and teacher of the gospel, or the preacher of “another Gospel”? In both cases it seems to me that zealous defenders of the doctrine are actually undermining their own credibility in many cases. –M. H.
Heidelberg Catechism #60:
How are thou righteous before God?
Only by a true faith in Jesus Christ; so that, though my conscience accuse me, that I have grossly transgressed all the commandments of God, and kept none of them, and am still inclined to all evil; notwithstanding, God, without any merit of mine, but only of mere grace, grants and imputes to me, the perfect satisfaction, righteousness and holiness of Christ; even so, as if I never had had, nor committed any sin: yea, as if I had fully accomplished all that obedience which Christ has accomplished for me; inasmuch as I embrace such benefit with a believing heart.
As the primary author of the Heidelberg Catechism, Zacharias Ursinus taught that Christ’s righteousness was imputed to believers. He expounded on what was entailed or meant by this doctrine in several places in his lectures on the Catechism, and approved a commentary from those notes.
Here are some comments from Ursinus on queston 61 of the Heidelberg Catechism which deal with the nature of the imputation of Christ’s righteousness:
The righteousness with which we are here justified before God, is not our conformity with the law, nor our good works, nor our faith; but it is the satisfaction which Christ rendered to the law in our stead; or the punishment which he endured in our behalf; and therefore the entire humiliation of Christ, from the moment of his conception to his glorification, including his assumption of humanity, his subjection to the law, his poverty, reproach, weakness, sufferings, death, &c., all of which he did willingly; yea, whatever he did and suffered to which he was not bound, as being righteous, and the Son of God, is all included in the satisfaction which he made for us, and in the righteousnoss which God graciously imputes to us, and all believers. This satisfaction is equivalent to the fulfilling of the law, or to the endurance of eternal punishment for sin, to one or the other of which the law binds all. “I determined not to know any thing among you, save Jesus Christ, and him crucified.” “Ye are complete in him.” “By the obedience of one shall many be made righteous.” “With his stripes we are healed.” “He was bruised for our iniquities.” “This cup is the new testament in my blood, which is shed for many for the remission of sins.” “Being justified freely, by his grace, through the redemption that is in Christ Jesus; whom God hath set forth to be a propitiation through faith in his blood.” “Blessed are they whose iniquities are forgiven.” “Being justified by his blood, we shall be saved from wrath through him.” “We were reconciled to God by the death of his Son.” “Though he was rich, yet for your sakes he became poor, that ye through his poverty might be rich.” “He redeemed us from the curse of the law, being made a curse for us.” “In whom we have redemption through his blood, the forgiveness of sins.” ” The blood of Jesus Christ his Son cleanseth us from all sin.” (1 Cor. 2: 2. Col. 2: 10. Rom. 5:19. Is. 53: 5, 6. Luke 22: 20. Rom. 3:24, 25; 4:7; 5:9, 10. 2 Cor. 8:9. Gal. 3:13. Eph.1:7. 1 John 1:7.) Christ fulfilled the law by the holiness of his human nature, and by his obedience, even unto the death of the cross. The holiness of his human nature was necessary to his obedience; for it became our mediator to be holy and righteous in himself, that he might be able to perform obedience, and make satisfaction for us. “For such an High Priest became us, who is holy,” &c. (Heb. 7: 26.) This obedience now is our righteousness, and it is upon the ground of this that God is pleased with us. The blood of Christ is the satisfaction on account of Which God receives us into his favor, and which he imputes unto us, as it is said, the blood of Jesus Christ his Son Cleanseth us from all sin, [emphasis original here] both of commission and omission. The shedding of his blood is the complement of his satisfaction, and is for this reason called our righteousness.
The questions, How can a rational creature be righteous before God? how can man, being a sinner, be just before God? and whether a rational creature can merit any thing at the hands of God? are to be distinguished from each other. We reply to the first question, that a rational creature may be just before God by an inherent conformity with the law, as the angels, and those that are blessed. To the second question we reply, that man as a sinner can be regarded as righteous only on the ground of the imputation of Christ’s merits; and this is the question of which we speak when treating the subject of justification. That man cannot be declared righteous upon the ground of his works is evident from this, that his works are unholy before his justification–that after his justification they are also imperfect, and that if they were perfect as they will be in another life, they could nevertheless, not satisfy for those sins which are past, and which still stand against us. To the third question we answer that man can merit nothing from God, for it is said, “When ye shall have done all those things which are commanded you, say, ‘We are unprofitable servants; we have done that which was our duty to do.’” (Luke 17:10.) Nor is the obedience of Christ meritorious in this respect, as though it added anything to God, but it is called meritorious on account of the dignity of his person, because he who suffered was the Son of God.
Ursinus explains “the satisfaction which Christ rendered to the law in our stead” as “the punishment which he endured in our behalf.” For Ursinus, the righteousness sinners receive in Christ by faith is a righteousness from Christ’s “passive obedience.” He does call it “obedience” to be sure, but nowhere do we find this obedience to be anything other than his willing suffering. When Ursinus calls Christ’s obedience meritorious, he immediately defines that obedience as suffering: “it is called meritorious on account of the dignity of his person, because he who suffered was the Son of God.”
Out of context, Ursinus’ mention of “subjection to the law” could be used to refer to “active obedience.” But that is obviously not what Ursinus meant. He says what he means several times: he means sufferings.
How “subjection to the law” would count as passive obedience in Ursinus’ mind is readily explained in his comments on the creed’s “He suffered” as found in question 37 of the Heidelberg catechism. His sufferings included “the temptations of the devil; ‘He was in all points tempted like as we are, yet without sin.’ (Heb. 4:15.)” (p. 213). Ursinus’ makes an initial comment on Christ’s sufferings that show how far active obedience was from his mind:
The passion or suffering of Christ is place immediately after his conception and nativity; 1. Because out entire salvation consists in his passion and death. 2. Because his whole life was one continued scene of suffering and privation (emphasis added).
Finally, Ursinus does deal with Christ’s active obedience in relationship to his passive obedience and this is what he says about it:
Q16: Why must He be a true and righteous man?
A16: Because the justice of God requires  that the same human nature which has sinned should make satisfaction for sin; but one who is himself a sinner cannot satisfy for others.
1. Rom. 5:15
2. Isa. 53:3-5
It behooved our Mediator to be man, and indeed very man, and perfectly righteous…
Thirdly, It behooved him to be a perfectly righteous man, one that was wholly free from the least stain of original and actual sin, that he might deservedly be our Savior, and that his sacrifice might avail, not for himself, but for us: for if he himself had been a sinner, he would have had to satisfy for his own sins…
If the Mediator himself had been a sinner he could not have escaped the wrath of God, much less could he have procured for others the favor of God, and exemption from punishment: neither could the passion, and death of him, who did not suffer as an innocent man, be a ransom for the sin of others.
Ursinus then quotes Second Corinthians 5.21 as one of his prooftexts that only a righteous man could have suffered to obtain “exemption from punishment”: “For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.”
In the next paragraph (bottom p. 86 to top of 87), Ursinus writes that “The man Christ was perfectly righteous, or has fulfilled the law in four respects,” which he then enumerates. The third fulfillment in the law is its fulfillment in us by his Spirit. The fourth fulfillment is his correct teaching of the law that frees it from errors that were being taught. Regarding the first two fulfillments, he writes:
1. By his own righteousness. Christ alone performed perfect obedience, such as the law requires. 2. By enduring punishment sufficient for our sins. There was a necessity that this double fulfillment of the law should be in Christ: for unless his righteousness had been full, and perfect, he could not have satifisfied for the sins of others; and unless he had endured such punishment as has been described, he could not thereby have delievered us from everlasting punishment. The former is called the fulfilling of the law by obedience, by which he himself was conformable thereto; the latter is the fulfilling of the law by punishment, whe he suffered for us, theat we might not remain subject to eternal condemnation.
Finally, Ursinus’ view of the requirements of the Law would lead us to expect him to find it impossible to conceive of a need for both Christ’s passive and active obedience imputed to the same person. He wrote:
This satisfaction is equivalent to the fulfilling of the law, or to the endurance of eternal punishment for sin, to one or the other of which the law binds all (emphasis added).
In Ursinus view one either needs to be perfectly obedient or one needs to have suffered eternal punishment. Jesus Christ perfectly obeyed the Law in order to qualify as a representative sufferer. He suffered an eternal punishment so that we could be counted as perfectly obedienct since the curse of the Law would have nothing more to do with us.