The first chapter of Jonathan Edwards’ End for Which God Created the World demonstrates that his doctrine is rational. In an age that was increasingly supposing that revelation and reason were diametrically opposed, Edwards wanted to prove that Scripture’s doctrine was very much reasonable. Revelation is the ultimate guide for any doctrine, but reason can help answer objections raised against what the Bible teaches.
Creation itself cannot be the chief reason for creating the world, or else God would be insufficient and need something external to himself. God’s being in and of itself cannot be God’s ultimate end, because they existed prior to God’s action. God’s chief end must be something valuable in creation and something creation itself can attain. This end must therefore also be prior to creation. Edwards continues,
That if God himself be, in any respect, properly capable of being his own end in the creation of the world, then it is reasonable to suppose that he had respect to himself, as his last and highest end, in this work; because he is worthy in himself to be so, being infinitely the greatest and best of beings. All things else, with regard to worthiness, importance, and excellence, are perfectly as nothing in comparison of him. And therefore, if God has respect to things according to their nature and proportions, he must necessarily have the greatest respect to himself. It would be against the perfection of his nature, his wisdom, holiness, and perfect rectitude, whereby he is disposed to do every thing that is fit to be done, to suppose otherwise.
In other words, God is himself the best and greatest being, and everything else are dependent on him for existence and far inferior to him. If God does not most value the greatest Being, i.e., himself, then his very holiness is called into question. Edwards goes on to elaborate on this last idea:
At least, a great part of the moral rectitude of God, whereby he is disposed to every thing that is fit, suitable, and amiable in itself, consists in his having the highest regard to that which is in itself highest and best. The moral rectitude of God must consist in a due respect to things that are objects of moral respect; that is, to intelligent beings capable of moral actions and relations. And therefore it must chiefly consist in giving due respect to that Being to whom most is due; for God is infinitely the most worthy of regard. The worthiness of others is as nothing to his; so that to him belongs all possible respect. To him belongs the whole of the respect that any intelligent being is capable of. To him belongs all the heart. Therefore, if moral rectitude of heart consists in paying the respect of the heart which is due, or which fitness and suitableness requires, fitness requires infinitely the greatest regard to be paid to God; and the denying of supreme regard here would be a conduct infinitely the most unfit. Hence it will follow, that the moral rectitude of the disposition, inclination, or affection of God chiefly consists in a regard to himself, infinitely above his regard to all other beings; or, in other words, his holiness consists in this.
One of the keys to this argument is that “moral rectitude” insists that heart duly give greatest honor that which most deserves it, that one most regard that which is most fittingly the recipient of that regard. God himself is one most worthy, most fitting, most deserving to receive that regard and honor. So for God to honor any thing other than himself calls into question his “moral rectitude,” and holiness. Edwards continues,
And if it be thus fit that God should have a supreme regard to himself, then it is fit that this supreme regard should appear in those things by which he makes himself known, or by his word and works, i.e. in what he says, and in what he does. If it be an infinitely amiable thing in God, that he should have a supreme regard to himself, then it is an amiable thing that he should act as having a chief regard to himself; or act in such a manner, as to show that he has such a regard: that what is highest in God’s heart, may be highest in his actions and conduct. And if it was God’s intention, as there is great reason to think it was, that his works should exhibit an image of himself their author, that it might brightly appear by his works what manner of being he is, and afford a proper representation of his divine excellencies, and especially his moral excellence, consisting in the disposition of his heart; then it is reasonable to suppose that his works are so wrought as to show this supreme respect to himself, wherein his moral excellence primarily consists.