IV. Though the parties concerned in the covenant, as explained in this answer, to wit, God the Father, and Christ the Head of his elect, are both divine Persons, so that one of them is not infinitely below the other, as man is below God; and therefore it is more properly called a covenant, in this respect, than that which God is said to enter into with man, (and, if stipulation and re-stipulation is, in any respect, applicable to the divine dispensation, it may be applied in this case:) nevertheless, there are some things, which are implied in the idea of a covenant between man and man, that cannot, consistently with the glory of these divine Persons, be contained in this federal transaction between them; particularly, as he that enters into covenant with another, proposes some advantage to himself hereby: thus a master, when he stipulates with one to be his servant, is supposed as much to need his service, as the servant does the wages that he promises to give him; there is a kind of mutual advantage arising from thence: but, in the covenant of grace, whether God be said to make it with man, or with Christ, as the Head of his elect, the advantage that arises from thence is our’s, and not God’s. In this respect, what was done by Christ, made no addition to the essential glory of God, or the divine blessedness, any more than man can be said, in that respect, to be profitable to him: thus some understand those words of the Psalmist, as spoken by our Saviour, when he says, _My goodness extendeth not to thee, but to the saints which are in the earth_, Psal. xvi. 2, 3. and this agrees very well with some other things, contained in the same Psalm, which are expressly, in other parts of scripture, applied to him; and, if so, then the meaning is, that whatever glory God the Father designed to demonstrate by this federal transaction with his Son; yet he did not, as men do, by entering into covenant with one another, propose to receive any addition of glory from it, as though he were really to be profited thereby.
Again, when men enter into covenant with one another, they are supposed to have different wills, and accordingly they might refuse to enter into those engagements, which they bring themselves under, as well as comply with them; the obligation, on both sides, is founded in mutual consent, and that is supposed to be arbitrary: but, when we consider the eternal compact between the Father and the Son, we must conclude, that though they be distinct as to their personality, yet, having the same essential perfections, the will of the Father and the Son, cannot but be the same. Therefore when many, who explain this doctrine, represent one as proposing, the other as complying, with the proposal; one demanding, the other expecting, and each depending on mutual promises, made by one to the other, this, it is true, seems to be founded on some scripture-expressions to the same purpose, wherein the Holy Ghost is pleased to condescend to make use of such modes of speaking, which are agreeable to the nature of human covenants, as he does in various other instances; nevertheless, we must not so far strain the sense of words, as to infer, from hence, any thing that is inconsistent with the divine glory of the Father and the Son. And to this we may add, that no act of obedience can be performed by a divine Person, in the same nature, as there cannot be an act of subjection in that nature, which is properly divine; and consequently when we consider Christ, in this respect, as entering into covenant, and engaging to perform those conditions, which were insisted on therein, these are supposed to be performed by him, as Mediator, or God incarnate, in his human nature; and, in this respect, he is the Head of the covenant, which is made with him, and, in him, with the elect. Therefore we must suppose, when we speak of a covenant between the Father and the Son, that, whatever be the will of the Father, the same is the Son’s will; and whatever conditions the Son consented to perform, as stipulated in this covenant, it was in his human nature that the work was to be done; and therefore it is well observed, in some following answers, that he, who is the Head or Mediator of this covenant, is, as it was absolutely necessary for him to be, both God and man, in one Person. But of this more hereafter.