The virtue of faith is a supernatural virtue whereby we believe truths revealed by God, and believe them on the authority of God revealing. It is to this "evidence" that Paul alludes when he describes faith as the "substance of things hoped for, the evidence of things unseen." (Hebrews 11:1) We believe, not because of the intrinsic truth of things seen by the natural light of reason, but because of the Divine authority which guarantees their truth. An act of faith is a supernatural assent of the intellect, most certain and free, whereby we believe a truth revealed by God on His Divine authority. This means it is:
- An intellectual assent under the dominion of the will and therefore free.
- Supernatural, because of the inspiration and illumination of the Holy Spirit.
- Absolutely certain and irrevocable, based on the authority of God. The assent is more certain than the antecedent judgment of credibility.
- An antecedent judgment that God has spoken.
- Free, even after the certain knowledge of credibility. The freedom is not only that of believing or not, but believing and disbelieving.
The object which is believed is either material or formal. The material object is the totality of revelation. It is divided into the object of faith per se, which cannot be known without revelation, and the preambles of faith. The object of faith per se is either formal or primary. i.e. intimate life of God, or other truths of revelation.
The formal object of faith is the authority of God revealing. The authority of God implies:
1. His truthfulness;
2. His infallible knowledge.
Revelation itself, as the uncreated and free act of God, belongs to the formal motive of faith. The testimony of the church does not belong to the formal motive, but is only a condition.
Intellectual assent is a judgment which may be doubtful, probable, or certain.
- Doubt- Intellect is not more inclined to accept a statement than to accept its contradictory.
- Opinion- Intellect inclined to accept a statement, though with fear of error.
- Certitude- In faith, it is divided into two categories:
- From the evidence of the object- Knowledge discursively reached.
- From the will- Object not evident, but accepted on the statement of a credible witness.
Since the intellect believes at the command of the will, the act of belief is free, because the object believed is not evident, and the motive is only one which influences the will to move the intellect to assent reasonably and firmly.
The virtue of faith must be supernatural and infused. Since the object to be believed (God and his intimate life) is essentially supernatural, the intellect of the believer must be proportioned to this object by a power essentially supernatural; belief must be infused by God and not acquired by humanity; and this is true not only for the faith of one in a state of grace, but for the faith of the sinner as well (preveient grace being operative).