IV. What are the efficient causes of faith?

The first and chief efficient cause of historical and temporary faith, as well as the faith of miracles, is the Holy Spirit, who produces these different kinds of faith by his general influence and operation. It is different, however, as it respects justifying faith, which the Holy Ghost produces by his special working. "By grace are ye saved, through faith, and that not of yourselves; it is the gift of God." (Eph. 2:8.)
Obj. The devil has historical faith. Therefore it is wrought in him by the Holy Ghost. Ans. The faith which is in devils is indeed produced by the Holy Ghost, but it is by his general working, as we have remarked; and not by his special influence, by which he works saving faith in the elect, and in them alone. For whatever knowledge devils and hypocrites possess, God produces in them by his Spirit; but not in such a manner as that he regenerates, or justifies them, as in the case of the elect; nor in such a manner that they may acknowledge and praise him as the author of this gift.
The instrumental cause of faith in general is the word of God, comprehended in the books of the Old and the New Testament, in which, beside the Word, there are also many divine works and miracles contained. The chief and peculiar instrument of justifying faith is the preaching of the gospel. "The gospel is the power of God unto salvation to every one that believeth." "Faith cometh by hearing, and hearing by the word of God." (Rom. 1:16; 10:17.) Justifying faith is, therefore, not ordinarily produced in adults without the preaching of the gospel.

The cause of that faith which works miracles, is not simply the word of God, but it requires a special promise, or revelation.

The formal cause of justifying faith is that which is peculiar to saving faith, which is a certain knowledge of all that God has revealed, and an assured confidence wrought in the heart.

The object of saving faith is Christ, and the promise of grace.

The subject, or part of man in which it exists, is the understanding, the will, and the heart.

The end or final cause is, first, the glory of God, or the manifestation of his righteousness, goodness, and mercy; and, secondly, our salvation.