III. It was requisite that the Mediator should be God and man, in one Person. Had his human nature been a distinct human Person, the work of our redemption would have been brought about by two persons, which would each of them have had the character of Mediator, unless two persons could be so united, as to constitute but one, which is no better than a contradiction. And it is farther observed, in the answer under our present consideration, that there were works to be performed, proper to each nature: in the human nature he was to perform every thing that implied subjection, obedience, or suffering; and though none of these could be performed by him, in his divine nature, yet an infinite worth, value, and dignity, was to be added thereunto, which was not so much the result of any thing done by him in that nature, as of the union of the human nature with it; upon which account, the obedience he performed, had, in a relative sense, the same value, as though it had been performed in his divine nature; and, upon this account, it is said, that _God purchased the church with his own blood_, Acts xx. 28. And to this we may add, that as each nature was distinct, and their properties not in the least confounded, as was before observed; so we often read, in scripture, of distinct properties attributed to the same person, which are opposed to each other, namely, mortality and immortality, weakness and omnipotency, dependence and independence, &c. which could not be, with any propriety of speaking, applied to him, had he not been God and man, in the same person. This is generally styled by divines, _a communication of properties_,[136] concerning which we must observe, that the properties of one nature are not predicated of the other; as the Lutherans suppose, when they conclude, that the human nature of Christ is omnipresent, upon which their doctrine of _consubstantiation_ is founded; but we assert, that the properties of one nature are predicated of the same person, to whom the other nature also belongs; so that when we say the Person, that was God, obeyed and suffered; or the Person, that was man, paid an infinite price to the justice of God, we are far from asserting, that the Godhead of Christ obeyed, or the manhood merited;[137] and this is the necessary result of his two natures being united in one Person. There are two things observed, in illustrating this matter.