Answ. It was requisite that the Mediator should be God, that he might sustain and keep the human nature from sinking under the infinite wrath of God, and the power of death, give worth and efficacy to his sufferings, obedience, and intercession; and so satisfy God’s justice, procure his favour, purchase a peculiar people, give his Spirit to them, conquer all their enemies, and bring them to everlasting salvation.
Quest. XXXIX. Why was it requisite that the Mediator should be Man?
Answ. It was requisite that the Mediator should be Man, that he might advance our nature, perform obedience to the law, suffer, and make intercession for us in our nature, have a fellow-feeling of our infirmities, that we might receive the adoption of sons, and have comfort and access with boldness unto the throne of grace.
Quest. XL. Why was it requisite that the Mediator should be God and Man in one Person?
Answ. It was requisite that the Mediator, who was to reconcile God and Man, should himself be both God and Man, and this in one Person, that the proper works of each nature might be accepted of God for us, and relied on by us, as the works of the whole Person.
Our Mediator having been considered as God and Man, in one person, we have a farther account of the necessity of being so. And,
I. It was necessary that he should be a divine Person, for several reasons here assigned, with others that may be added. As,
1. If he had not been God, he could not have come into the world, or been incarnate, and have had the guilt of our sins laid on him, with his own consent; for he could not have been a party in the everlasting covenant, in which this matter was stipulated between the Father and him; and, had he not consented to be charged with the guilt of our sin, he could not have been punished for it, inasmuch as God cannot punish an innocent person; and, if such an one be charged with this guilt, and consequently rendered the object of vindictive justice, as our Saviour is said to have been, in scripture, it must be with his own consent. Now the human nature could not consent to its own formation, and therefore it could not consent to bear our iniquities; since to consent supposes the person to be existent, which Christ, had he been only Man, would not have been before his incarnation, and therefore he could not have come into the world as a Surety for us, and so would not have been fit, in this respect, to have discharged the principal part of the work, which he engaged in as Mediator.
2. There is another thing, mentioned in this answer, which rendered it requisite that the Mediator should be God, namely, that he might sustain and keep the human nature from sinking under the infinite wrath of God, and the power of death. It must be allowed, that the weight of the wrath of God, due to our sin, was so great, that no mere creature could, by his own strength, have subsisted under it. We will not deny, that a mere creature, supposing him only innocent, but not united to a divine Person, might have been borne up, under the greatest burthen laid on him, by the extraordinary assistance of God, with whom all things are possible; nor that God’s giving a promise that he should not fail, or be discouraged, is such a security, as would effectually keep it from sinking; yet when we consider the human nature, as united to the divine, this is an additional security, that he should not sink under the infinite weight of the wrath of God, that lay upon him; for then it would have been said, that he, who is a divine Person, miscarried in an important work, which he undertook to perform in his human nature, which would have been a dishonour to him: so far this argument hath its proper force. But,
3. There is another reason, which more fully proves the necessity of the Mediator’s being a Divine Person, viz. that this might give worth and efficacy to his sufferings, obedience, and intercession, that so what he did might have a tendency to answer the valuable ends designed thereby, namely, the satisfying the justice of God, procuring his favour, and purchasing a peculiar people to himself. Had he been only man, what he did and suffered, might indeed have been sinless, and perfect in its kind; nevertheless, it could not be of infinite value, for a finite creature, as such, cannot pay an infinite price, and thereby answer the demands of justice. Had nothing been demanded of him but a debt of obedience, which he was obliged to perform for himself, as a creature, it would not, indeed, have been necessary that it should be of infinite worth and value, any more than that obedience, that was due from our first parents, while in a state of innocency: But when this is considered as a price of redemption paid for us, and as designed to procure a right to the favour of God, and eternal life, this must be of such a value, that the glory of the justice of God might be secured, which nothing less than an infinite price could do; and the law of God must not only be fulfilled, but magnified, and made honourable; and therefore the obedience, which was required, must not only be sinless, but have in it an infinite worth and value, that hereby, when in a way of intercession, it is pleaded before God, it might be effectual to answer the ends designed thereby; but this it could not have been, had he not been an infinite Person, namely, God as well as Man.