(3) Whether it is proper to man to be adopted to the sonship of God?
(4) Whether Christ can be called the adopted Son? _______________________
FIRST ARTICLE [III, Q. 23, Art. 1]
Whether It Is Fitting That God Should Adopt Sons?
Objection 1: It would seem that it is not fitting that God should adopt sons. For, as jurists say, no one adopts anyone but a stranger as his son. But no one is a stranger in relation to God, Who is the Creator of all. Therefore it seems unfitting that God should adopt.
Obj. 2: Further, adoption seems to have been introduced in default of natural sonship. But in God there is natural sonship, as set down in the First Part (Q. 27, A. 2). Therefore it is unfitting that God should adopt.
Obj. 3: Further, the purpose of adopting anyone is that he may succeed, as heir, the person who adopts him. But it does not seem possible for anyone to succeed God as heir, for He can never die. Therefore it is unfitting that God should adopt.
On the contrary, It is written (Eph. 1:5) that "He hath predestinated us unto the adoption of children of God." But the predestination of God is not ineffectual. Therefore God does adopt some as His sons.
I answer that, A man adopts someone as his son forasmuch as out of goodness he admits him as heir to his estate. Now God is infinitely good: for which reason He admits His creatures to a participation of good things; especially rational creatures, who forasmuch as they are made to the image of God, are capable of Divine beatitude. And this consists in the enjoyment of God, by which also God Himself is happy and rich in Himself—that is, in the enjoyment of Himself. Now a man's inheritance is that which makes him rich. Wherefore, inasmuch as God, of His goodness, admits men to the inheritance of beatitude, He is said to adopt them. Moreover Divine exceeds human adoption, forasmuch as God, by bestowing His grace, makes man whom He adopts worthy to receive the heavenly inheritance; whereas man does not make him worthy whom he adopts; but rather in adopting him he chooses one who is already worthy.
Reply Obj. 1: Considered in his nature man is not a stranger in respect to God, as to the natural gifts bestowed on him: but he is as to the gifts of grace and glory; in regard to which he is adopted.