Reply Obj. 2: Before Christ's coming, faith in the Trinity lay hidden in the faith of the learned, but through Christ and the apostles it was shown to the world.
Reply Obj. 3: God's sovereign goodness as we understand it now through its effects, can be understood without the Trinity of Persons: but as understood in itself, and as seen by the Blessed, it cannot be understood without the Trinity of Persons. Moreover the mission of the Divine Persons brings us to heavenly happiness. _______________________
NINTH ARTICLE [II-II, Q. 2, Art. 9]
Whether to Believe Is Meritorious?
Objection 1: It would seem that to believe is not meritorious. For the principle of all merit is charity, as stated above (I-II, Q. 114, A. 4). Now faith, like nature, is a preamble to charity. Therefore, just as an act of nature is not meritorious, since we do not merit by our natural gifts, so neither is an act of faith.
Obj. 2: Further, belief is a mean between opinion and scientific knowledge or the consideration of things scientifically known [*Science is a certain knowledge of a demonstrated conclusion through its demonstration.]. Now the considerations of science are not meritorious, nor on the other hand is opinion. Therefore belief is not meritorious.
Obj. 3: Further, he who assents to a point of faith, either has a sufficient motive for believing, or he has not. If he has a sufficient motive for his belief, this does not seem to imply any merit on his part, since he is no longer free to believe or not to believe: whereas if he has not a sufficient motive for believing, this is a mark of levity, according to Ecclus. 19:4: "He that is hasty to give credit, is light of heart," so that, seemingly, he gains no merit thereby. Therefore to believe is by no means meritorious.
On the contrary, It is written (Heb. 11:33) that the saints "by faith . . . obtained promises," which would not be the case if they did not merit by believing. Therefore to believe is meritorious.
I answer that, As stated above (I-II, Q. 114, AA. 3, 4), our actions are meritorious in so far as they proceed from the free-will moved with grace by God. Therefore every human act proceeding from the free-will, if it be referred to God, can be meritorious. Now the act of believing is an act of the intellect assenting to the Divine truth at the command of the will moved by the grace of God, so that it is subject to the free-will in relation to God; and consequently the act of faith can be meritorious.
Reply Obj. 1: Nature is compared to charity which is the principle of merit, as matter to form: whereas faith is compared to charity as the disposition which precedes the ultimate form. Now it is evident that the subject or the matter cannot act save by virtue of the form, nor can a preceding disposition, before the advent of the form: but after the advent of the form, both the subject and the preceding disposition act by virtue of the form, which is the chief principle of action, even as the heat of fire acts by virtue of the substantial form of fire. Accordingly neither nature nor faith can, without charity, produce a meritorious act; but, when accompanied by charity, the act of faith is made meritorious thereby, even as an act of nature, and a natural act of the free-will.