Faith is confidence or trust in a person or entity. In religion, faith is belief in God or gods or in the doctrines or teachings of the religion. Informal usage of faith can be quite broad, including trust or belief without proof, and "faith" is often used as a substitute for "hope", "trust" or "belief".
Some critics of faith have argued that faith is opposed to reason. In contrast, some advocates of faith argue that the proper domain of faith concerns questions which cannot be settled by evidence. This is exemplified byattitudes about the future, which (by definition) has not yet occurred. Logical reasoning may proceed from any set of assumptions, positive or negative. In this view, faith is simply a positive assumption.
The English word is thought to date from 1200–50, from the Middle English feith, via Anglo-French fed, Old French feid, feit from Latinfidem, accusative of fidēs (trust), akin to fīdere (to trust).
There exists a wide spectrum of opinion with respect to the epistemological validity of faith. On one extreme is logical positivism, which denies the validity of any beliefs held by faith; on the other extreme is fideism, which holds that true belief can only arise from faith, because reason and physical evidence cannot lead to truth. Some foundationalists, such as St. Augustine of Hippo and Alvin Plantinga, hold that all of our beliefs rest ultimately on beliefs accepted by faith. Others, such as C.S. Lewis, hold that faith is merely the virtue by which we hold to our reasoned ideas, despite moods to the contrary.
William James believed that the varieties of religious experiences should be sought by psychologists, because they represent the closest thing to a microscope of the mind—that is, they show us in drastically enlarged form the normal processes of things. For a useful interpretation of human reality, to share faith experience he said that we must each make certain "over-beliefs" in things which, while they cannot be proven on the basis of experience, help us to live fuller and better live