Zacharius Ursinus explains what the Heidelberg Catechism means by its 37th question and answer in his fine commentary. The Catechism reads:
Question 37. What dost thou understand by the words, “He suffered”?
Answer: That he, all the time that he lived on earth, but especially at the end of his life, sustained in body and soul, the wrath of God against the sins of all mankind: that so by his passion, as the only propitiatory sacrifice, he might redeem our body and soul from everlasting damnation, and obtain for us the favor of God, righteousness and eternal life.
Christ satisfied for all, as it respects the sufficiency of the satisfaction which he made, but not as it respects the application thereof; for he fulfilled the law in a two-fold respect. First, by his own righteousness; and secondly, by making satisfaction for our sins, each of which is most perfect. But the satisfaction is made ours by an application, which is also two-fold; the former of which is made by God, when he justifies us on account of the merit of his Son, and brings it to pass that we cease from sin; the latter is accomplished by us through faith. For we apply unto ourselves, that merit of Christ, when by a true faith, we are fully persuaded that God for the sake of the satisfaction of his Son, remits unto us our sins. Without this application, the satisfaction of Christ is of no benfit to us. (pg. 215)
He also takes up the specifics around Q&A 40 in regards to whom Christ died for. This is quite helpful in understanding the logic behind Ursinus’s view of penal substitution and limited atonement:
They affirm, therefore, that Christ died for all, and that he did not die for all; but in different respects. He died for all, as touching the sufficiency of the ransom which he paid; and not for all; but only for the elect, or those that believe, as touching the application and efficacy thereof. The reason of the former lies in this, that the atonement of Christ is sufficient for expiating all the sins of all men, or of the whole world, if only all men will make application thereof unto themselves by faith. For it cannot be said to be insufficient, unless we give countenance to that horrible blasphemy (which God forbid!) that some blame of the destruction of the ungodly results from a defect in the merit of the mediator. The reason of the latter is, because all the elect, or such as believe, and they alone, do apply unto themselves by faith the merit of Christ’s death, together with the efficacy thereof, by which they obtain righteousness, and life according as it is said, “He that believeth on the Son of God, hath everlasting life.” (John 3:36.) The rest are excluded from this efficacy of Christ’s death by their own unbelief, as it is again said, “He that believeth not shall not see life, but the wrath of God abideth on him.” (John 3:36.) Those, therefore, whom the Scriptures exclude form the efficacy of Christ’s death, cannot be said to be included in the number of those for whom he died as it respects the efficacy of his death, but only as to its sufficiency; because the death of Christ is also sufficient for their salvation, if they will but believe; and the only reason of their exclusion arises from their unbelief.
It is in the same way, that is, by making the same distinction that we reply to those who ask concerning the purpose of Christ, Did he will to die for all? For just as he died, so also he willed to die. Therefore, as he died for all, in respect to the sufficiency of his ransom; and for the faithful alone in respect to the efficacy of the same, so also he willed to die for all in general, as touching the sufficiency of his merit, that is, he willed to merit by his death, grace, righteousness, and life in the most abundant manner for all; because he would not that any thing should be wanting as far as he and his merits are concerned, so that all the wicked who perish may be without excuse. But he willed to die for the elect alone as touching the efficacy of his death, that is, he would not only sufficiently merit grace and life for them alone, but also effectually confers these upon them, grants faith, and the holy Spirit, and brings it to pass that they apply to themselves, by faith, the benefits of his death, and so obtain for themselves the efficacy of his merits. (pg. 223)
Now it is important to keep a few distinctions in mind. Those communions who subscribe to the Heidelberg catechism are confessionally bound to teach that Jesus “sustained in body and soul, the wrath of God against the sins of all mankind.” This much is simply a statement of fact.
They may turn to Ursinus’s commentary for an explanation of how to interpret this statement, of course, and that would be what any responsible student ought to do. Let us then review Ursinus’s logic.
First, Christ satisfied for all in regards to sufficiency. This has to do with the content of the actual death. The “stuff” of the cross, if we may be permitted to use such language for now. This satisfaction is objective and “enough” to remit the sins of the whole world if individuals would but apply the satisfaction. This satisfaction includes the merit of Christ’s death, grace, righteousness, and life. This is the content of Christ’s satisfaction, and it is rightly preached to be “for all” so that no one can complain or evade personal responsibility for not possessing it. The satisfaction is made, and all are invited to apply it by faith.
The limitation, according to Ursinus, occurs in the effectual call of the elect. Christ not only provides the satisfaction, but also “effectually confers these upon them [the elect], grants faith, and the holy Spirit, and brings it to pass that they apply to themselves, by faith, the benefits of his death, and so obtain for themselves the efficacy of his merits.”
That which is conferred is the same in content as that which is made by Christ. The distinction is in the application.
This is important for a number of reasons. It provides a basis for the free offer of the gospel, as well as the ability to state that all are without excuse if they do not make application of Christ’s satisfaction. This reading is consistent with Dort, and thus explains how Dabney could claim his position as the Reformed position centuries later.