The word faith, according to Cicero, is derived from fiendo, which signifies doing, because that which is declared is performed. It is, according to him, the assurance, the truth of contracts, and of whatever may be spoken, and is the foundation of justice.
According to the common definition, faith is a certain knowledge of facts, or conclusions, to which we assent on the testimony of faithful witnesses, whom we may not disbelieve, whether it be God, or angels, or men, or experience.
But since, according to the most general distinction, there is one kind of faith in divine, and another in human affairs, we must here inquire, what is faith in divine things, or what is theological faith? The definition of faith, therefore, taken generally, must be given somewhat more exactly, and yet it must be such as to comprise in it all the different forms of faith spoken of in the Scriptures.
Faith, in general, of whatever kind mention is made in the Holy Scriptures, is an assent to, or a certain knowledge of what is revealed concerning God, His will, works, and grace, in which we confide upon divine testimony. Or, it is to yield assent to every word of God delivered to the church, in the law and gospel, on account of the declaration of God Himself.
Faith is, also, often taken for the doctrine of the church, or for those things of which the word of God informs us, and which are necessary to faith, as when it is called the Christian faith, the Apostolic faith. It is, likewise, often used for the fulfillment of ancient promises, or for the things themselves, which are believed; as “Before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed.” (Galatians 3:23)