"3. God’s Design and Result Exactly Co-Extensive.
There is no safer clue for the student through this perplexed subject, than, to take this proposition; which, to every Calvinist, is nearly as indisputable as a truism; Christ’s design in His vicarious work was to effectuate exactly what it does effectuate, and all that it effectuates, in its subsequent proclamation. This is but saying that Christ’s purpose is unchangeable and omnipotent. Now, what does it actually effectuate? 'We know only in part,' but so much is certain.
(a.) The purchase of the full and assured redemption of all the elect, or of all believers.
(b.) A reprieve of doom for every sinner of Adam’s race who does not die at his birth (For these we believe it has purchased heaven). And this reprieve gains for all, many substantial, though temporal benefits, such as unbelievers, of all men, will be the last to account no benefits. Among these are postponement of death and perdition, secular well being, and the bounties of life.
(c.) A manifestation of God’s mercy to many of the non-elect, to all those, namely, who live under the Gospel, in sincere offers of a salvation on terms of faith. And a sincere offer is a real and not a delusive benefaction; because it is only the recipient's contumacy which disappoints it.
(d.) A justly enhanced condemnation of those who reject the Gospel, and thereby a clearer display of God’s righteousness and reasonableness in condemning, to all the worlds.
(e.) A disclosure of the infinite tenderness and glory of God’s compassion, with purity, truth and justice, to all rational creatures.
Had there been no mediation of Christ, we have not a particle of reason to suppose that the doom of our sinning race would have been delayed one hour longer than that of the fallen angels. Hence, it follows, that it is Christ who procures for non-elect sinners all that they temporarily enjoy, which is more than their personal deserts, including the sincere offer of mercy. In view of this fact, the scorn which Dr. William Cunningham heaps on the distinction of a special, and general design in Christ’s satisfaction, is thoroughly shortsighted. All wise beings (unless God be the exception), at times frame their plans so as to secure a combination of results from the same means. This is the very way they display their ability and wisdom. Why should God be supposed incapable of this wise and fruitful acting? I repeat, the design of Christ’s sacrifice must have been to effectuate just what it does effectuate. And we see, that, along with the actual redemption of the elect, it works out several other subordinate ends. There is then a sense, in which Christ 'died for' all those ends, and for the persons affected by them" (R.L. Dabney, Lectures on Systematic Theology, pp. 528-529).