What does a person mean when somebody says they have faith in something but don't know that something to be true? Is this a psychological evasion?

It might help to think of such faith as akin to trust. We can trust a hunch about who will win a game without knowing that we are right; and we can trust a stranger to help us without knowing that they will do so. Some philosophers think that such trust can be reasonable because our unreflective inclinations are usually based on some information, whether or not we recognize what it is. The hunch about the winner is based on something we have observed, perhaps unconsciously; and the expectation of a stranger's help is based on some innate recognition that most people are 'programmed' to be helpful to others. Other philosophers think that such trust can be reasonable because it tends to tip the balance in favor of the state in question -- the trusted player being more likely to win in virtue of our trust, and the trusted stranger more likely to help in virtue of our trust. Thus, while we may sometimes trust as a way of evading either the effort or the anticipated outcome of carefully...

Is the feeling that God exists a sufficient reason to believe in God? Is there anyway of analyzing such a feeling to determine its validity? Can feeling ever give us profound truths about the world?

Generally, feeling that something is true is a reason to believe that it is true (since our feelings are frequently based on true observations and ideas), but it is not a sufficient reason (since our feelings may arises from wishes rather than observations, and since there are many observations and ideas that are not reflected in our feelings). Insofar as you want to arrive at a warranted belief, rather than trying to analyze your feeling (which is extremely difficult to do honestly, and well), you should consider a wider range of feelings, and observations, and ideas in relation to each other. This is not something that can be done in a moment, and it cannot be done according to a rule; but it is the only way to be fully reasonable about your beliefs. It is certainly possible for feelings to reveal profound truths -- even if their truth cannot be established or confirmed by feeling alone. A feeling of horror, for example, may reveal the deep immorality of certain...

Is it still possible today to consider the notion of "obviousness" as a criterion of truth ?

All arguments seek premises that most people can agree to without needing further support, and in this sense the appeal to what is "obvious" remains alive and well. What people can agree to without further support often depends on the context, however: in the context of a weekend stroll, it may be obvious that there is a goldfinch nearby, whereas in the context of an official birdcount this may be less obvious. It is more accurate to call obviousness a criterion of knowledge rather than a criterion of truth , since the obviousness of a certain claim may be part of what makes my state a state of knowledge but it is not a part of what makes it true. The fact that a bird ate the seed will be true (or false) regardless of how obvious it is to me. The fact that is is obvious to me may, however, contribute to my view counting as knowledge. Note that obviousness may be a criterion of knowledge without being either necessary or sufficient for knowledge. Much of what we know (about the...