You say, “Moral justice cannot take the innocent for the guilty, even if the innocent were to offer itself; to suppose justice to do this, is to destroy the principle of its existence, which is the thing itself; it is then no longer justice, it is indiscriminate revenge.” Before this question can be decided, we must inquire, What is moral justice, as it applies to God? That it must be something different with him, from what it is with us, will appear from this consideration: God can, when, how, or where he pleases, deprive men of their lives, without any visible cause for such actions; yet God, notwithstanding this, is morally just in all his ways. Apply this to man; we cannot, consistently with moral justice, deprive men of their lives, without a previous forfeiture of the same to moral justice. Unless the cause of death, with us, be equal to the death inflicted, the act is injustice, and the death assassination and murder; but God cannot commit murder; therefore the deprivation of life, of any of his creatures, by him, must not only be reconcilable with justice, but founded on its very principles and nature. Neither can God be guided by the same laws, nor actuated by the same motives, with which we are. To talk of laws, and apply them both to God and man, is derogatory to his nature, for the reasons assigned above; and that, which derogates from God, cannot be applied to him. The rules, which regulate his ways and conduct in the economy of things, are such as we know little of; and what is justice with God, will in many cases, be injustice with us. It is a principle, which must be admitted, that the same power, which has a right to establish a law, must have a right to repeal that law; but God had a morally just right to establish, both the laws of nature, and the laws of his word; therefore, he has the same morally just right to suspend, or finally repeal either.

Nor does the exercise of this right, charge him with mutability; for, if the conduct of God invariably tends to promote human happiness, consistently with the freedom of man, his immutability must remain entire, while that end is kept in view. The mutability of man renders a change of means in God absolutely necessary, in order to preserve the stability of his original purposes: for a uniform application of the same measures, through all the vicissitudes of human instability, instead of uniformly tending towards human happiness, must tend, in many instances, to the completion of human misery: and, in this case, God might be justly charged with mutability, in deserting those purposes and designs which he once promoted. But, in all the apparent variations which we discover, in the moral, as well as the natural world, he is no more chargeable with mutability, than the mariner, who alters his course and shifts his sails, through the progress of his voyage, to arrive at the port of his destination.

These things being premised, the question is, whether God can so far accept a vicarious sacrifice, in the person of the innocent, as to permit his mercy to interfere in the behalf of the guilty. The question is not, in the present case, whether moral justice can accept the innocent for the guilty; but, whether God by receiving, in suffering, an equivalent for the offence committed, can, on a principle of mercy, discharge the guilty; and do this, as it relates to himself, consistently with the rectitude and justice of his nature.

As salvation is uniformly ascribed, in the Bible, to mercy, the question simply is, whether God can possibly show mercy, without being unjust. In the nature of things, justice cannot show mercy; for if any act be of justice, it is no longer of mercy;  nevertheless, mercy, when
exercised, must be so consistent with justice, that it cannot be unjust. Now, admitting the existence of moral evil in man, and the existence of moral justice in God, it follows, that these cannot meet together, without destroying human happiness; because the two principles are incompatible with each other. To destroy this incompatibility, either moral evil or moral justice must cease. It cannot be moral justice; therefore, it must be moral evil. But, admitting that moral evil could be extracted from the human mind without any expiation, still, the turpitude of those actions, which resulted from the evil principle, while it predominated, being a positive insult offered to moral justice, necessarily requires an expiation, in order to its annihilation. This expiation must, in order to be available, be abstracted from all evil; but, all mankind being infected by evil, no one, among the human race was adequate to the task. It must then follow, that some other substitute must be found; and we find every necessary qualification concentrated in the person of Jesus Christ.

That moral justice is obligatory on man, must be admitted; and then it must follow, that every deviation from that principle, subjects to punishment; this is evident, from our standing in need of mercy; and, if justice has an additional claim upon every offender, it must also follow, that his claim cannot be relinquished without an expiation: to suppose otherwise, is to reduce justice to an indiscriminate caprice. This claim must be cancelled, either by man or God. If by man,
it destroys every idea of future happiness; if by God, it must be, by accepting the innocent for the guilty. But, as the hope of future happiness is not destroyed, the claim must be cancelled by God: and, consequently, it must be by his accepting the innocent instead of the guilty.

Nor can justice accept of an offering made by one guilty person in the behalf of another; for, wherever guilt is found, it entitles its possessor to punishment; and punishment cannot have any thing in it meritorious. Nothing but merit can be available for the guilty; and, therefore, guilt must be expiated by innocence; which innocence must be so far accepted by commutative justice, as to permit mercy to operate in the behalf of the guilty. Finally, if we allow ourselves to be guilty, and God to be just, and yet hope for happiness from him, it must be admitted, that he can accept the innocent in the room of the guilty; and, that he does, in mercy, discharge them, and render them capable of happiness, through the efficacy of suffering innocence. And, if we grant mercy to exist with God, it must be, to entitle those who are the objects of it, to those favours, to which, through justice, they can have no claim.