Faith is a ‘new’ way of knowing in TOK, so the fact that it hasn’t previously been included perhaps gives us a clue about its nature. Because it does not rely on proof (indeed, proof not only isn’t required, but often clashes with the knowledge it provides) it isn’t accepted as a valid WOK. For others, it’s the basis of their whole lives. The OED defines it like this…
1 complete trust or confidence in someone or something: this restores one’s faith in politicians; 2 strong belief in the doctrines of a religion, based on spiritual conviction rather than proof: bereaved people who have shown supreme faith, a particular religion: the Christian faith, a strongly held belief: men with strong political faiths
It’s important to point out that faith doesn’t necessarily have to involve religion – as indicated by the first definition here – and can just indicate a close affiliation or trust in someone, some organisation, or some movement, such as a parent, a political party, or even a football team.
Knowledge question associated with faith include: To what extent should non-religious beliefs (such as atheism and humanism) be termed ‘faiths’? Does faith provide us with true knowledge? Can you understand religious belief systems without faith? Is doubt a part of faith?