In religious contexts, "faith" means trust or belief in God (or the gods) of one's religion. It also refers to the belief that one's religious tenets are true.
It is in the latter sense in which one can speak of, for example, "the Catholic faith" or "the Islamic faith."
Often religious believers use the term "faith" in a different way, as the affirmation of belief without an ongoing test of evidence, and even despite evidence apparently to the contrary. Most Jews, Christians and Muslims admit that whatever particular evidence or reason they may possess that God exists and is deserving of trust, is not ultimately the basis for their believing. Thus, in this sense faith refers to belief beyond evidence or logical arguments, sometimes called "implicit faith".
This is not to say that religious believers hold that their faith is baseless; many typically hold that there is some evidence and some logic which leads them to believe in God. However, they do not maintain that the evidence and logic themselves are sufficient to constitute proof or to justify the strength of their belief. The believer may believe without expectation of proof, so that if particular evidence is removed, or logic disproven, faith in this sense may nevertheless remain unshaken.
On the other hand, many Jews, Christians and Muslims claim that there is adequate historical evidence of God's existence and interaction with human beings. As such, there is no need for "faith" in God in the sense of belief against or despite evidence; rather, they hold that evidence is sufficient to demonstrate that God certainly exists, and that particular beliefs, concerning who or what God is and why God is to be trusted, are vindicated by evidence and logic. For people in this category, "faith" in God simply means "belief that one has knowledge of God". What is believed concerning God, in this sense, is at least in principle only as reliable as the evidence and the logic by which faith is supported.
Many religious rationalists, as well as non-religious people, criticise implicit faith as being irrational. In this view, belief should be restricted to what is directly supportable by logic or evidence.
There is a wide variety of views about the role of faith in religion. One view, fideism, has it that one ought to believe that God exists, but one should not base that belief on any other beliefs; one should, instead, accept it without any reasons at all. Faith in this sense, grounded simply in the sincerity of faith, belief on the basis of believing, is often associated with Soren Kierkegaard for example, and some other existentialist religious thinkers; his views are presented in Fear and Trembling.
In the Hebrew Bible the Hebrew word emet ("faith") does not mean belief in a dogmatic sense. Rather, it connotes (a) faithfulness (from the passive form "ne'eman" = "trusted" or "trustworthy,") or (b) confidence and trust in God and in God's word.
Jewish theology holds that faith in God is highly meritorious, but is not mandatory. While a person should believe in God, what matters most is if that person lives a decent life. Jewish rationalists, such as Maimonides, hold that faith in God, as such, is vastly inferior to coming to accept that God exists through compelling proofs. See the article on Jewish principles of faith for more details on Jewish theology.
The word "faith", translated from the Greek πιστις (pi´stis), primarily conveys the thought of confidence, trust, firm persuasion. Depending on the context, the Greek word may also be understood to mean "faithfulness" or "fidelity".-1Th 3:7; Tit 2:10.
Commenting on the function of faith in relation to the covenant of God, the writer of the letter to the Hebrews says, "Now faith is the assurance of things hoped for, the conviction of things not seen."(Heb 11:1 ESV). Πιστις, translated "faith" here, commonly appears in ancient papyrus business documents, conveying the idea that a covenant is an exchange of assurances which guarantees the future transfer of possessions described in the contract. In view of this, Moulton and Milligan suggest the rendering: "Faith is the title deed of things hoped for." (Vocabulary of the Greek Testament, 1963, p. 660) Hebrews 11:6 further illustrates the meaning and the practical role of faith: "without faith it is impossible to please [God], for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him.".
Summarizing the New Testament concept of faith, it is a reliance upon God's self-revelation, especially in the sense of confidence in the promises and fear of the threats that are written in Scripture. The writers evidently suppose that their concept of faith is rooted in the Hebrew Scriptures.
In addition, the New Testament writers conflate or equate faith in God with belief in Jesus. The Gospel of John is particularly emphatic on this point, having Jesus say, "The Father judges no one, but has given all judgment to the Son, that all may honor the Son, just as they honor the Father. Whoever does not honor the Son does not honor the Father who sent him." (John 5:22, 23). When asked "What must we do to do the works God requires?", the writer has Jesus answering, ""The work of God is this: to believe in the one he has sent." (John 6:28,19)
In the words of the Westminster Shorter Catechism: "Faith in Jesus Christ is a saving grace, whereby we receive and rest upon him alone for salvation, as he is offered to us in the gospel". The object of saving faith is the whole revealed Word of God. Faith accepts and believes it as the very truth most sure. But the special act of faith which unites to Christ has as its object the person and the work of the Lord Jesus Christ (John 7:38; Acts 16:31). This is the specific act of faith by which a sinner is justified before God (Rom. 3:22, 25; Gal. 2:16; Phil. 3:9; John 3:16-36; Acts 10:43; 16:31).
The basis for faith is divine testimony, not the reasonableness of what God says, but the simple fact that he says it. Faith rests immediately on, "Thus saith the Lord." But in order to this faith the veracity, sincerity, and truth of God must be owned and appreciated, together with his unchangeableness.
[Text adapted from Easton's Bible Dictionary ]
Faith is the sum of truths revealed by God in Scripture and tradition and which the Church presents to us in a brief form in her creeds, subjectively, faith stands for the habit or virtue by which we assent to those truths.
"We believe", says the Vatican Council (III, iii), "that revelation is true, not indeed because the intrinsic truth of the mysteries is clearly seen by the natural light of reason, but because of the authority of God Who reveals them, for He can neither deceive nor be deceived." Thus, with regard to the act of faith which the Christian makes in the Holy Trinity, faith can be described in a syllogistic fashion, thus:
Text adapted from The Catholic Encyclopedia article "Faith"
See also Faith and rationality, Scientific method, Rationalism, Wishful thinkingHebrew Bible
Judaism
New Testament
Protestantism
Faith is a kind of knowledge
Knowledge is an essential element in all faith, and is sometimes spoken of as an equivalent to faith (John 10:38; 1 John 2:3). Yet the two are distinguished in this respect, that faith includes in it assent, which is an act of the will in addition to the act of the understanding. Faith is an operation of the Spirit of God
Assent to the truth is of the essence of faith, and the ultimate ground on which our assent to any revealed truth rests is the veracity of God. Historical faith is the apprehension of and assent to certain statements which are regarded as mere facts of history. Temporary faith is that state of mind which is awakened in men (e.g., Felix) by the exhibition of the truth and by the influence of religious sympathy, or by what is sometimes styled the common operation of the Holy Spirit. Saving faith is so called because it has eternal life inseparably connected with it, and is a special operation of the Holy Spirit.The warrant of faith is the truthfulness of God
Catholicism
Faith is a supernatural act
Faith is a supernatural act performed by Divine grace. It is "the act of the intellect assenting to a Divine truth owing to the movement of the will, which is itself moved by the grace of God" (St. Thomas, II-II, Q. iv, a. 2). And just as the light of faith is a gift supernaturally bestowed upon the understanding, so also this Divine grace moving the will is, as its name implies, an equally supernatural and an absolutely gratuitous gift. Neither gift is due to previous study neither of them can be acquired by human efforts, but "Ask and ye shall receive." Faith not blind
Whatever God reveals is true
but, God has revealed the Holy Trinity, which is a mystery
therefore this mystery is true.
Roman Catholics accept the major premise as being beyond doubt, a presupposition upon which reason is based and thus intrinsically evident to reason; the minor premise is also true because it is declared by the Church, which is held to be infallible in its declarations, and also because, as the Vatican Council says, "in addition to the internal assistance of His Holy Spirit, it has pleased God to give us certain external proofs of His revelation, viz. certain Divine facts, especially miracles and prophecies, for since these latter clearly manifest God's omnipotence and infinite knowledge, they afford most certain proofs of His revelation and are suited to the capacity of all." Hence Thomas Aquinas writes: "A man would not believe unless he saw the things he had to believe, either by the evidence of miracles or of something similar" (II-II:1:4, ad 1). Thomas is here speaking of the motives of credibility, the causes which give rise to belief.