Faith comes from Latin Fides, and Greek Pitis. Of course these were also goddesses in Rome and Greece.
Eva Cassidy sings about Faith in the song People Get Ready..
People get ready
There's a train a-coming
You don't need no baggage
You just get on board
All you need is faith
To hear diesels humming
You don't need no ticket
You just thank the Lord
Yeah yeah yeah
People get ready
For the train to Jordan
Picking up passengers
From coast to coast
Faith is the key
Open the doors and board them
There's room for all
Among the loved and lost
The bible describes Pitis as a feminine noun, meaning trust, confidence, fidelity, and faithfulness.
Pistis comes from the word, Petiho, persuade, be persuaded,
It describes faith as a gift from God and not something that can be produced by people. ("faith") for the believer is "God's divine persuasion" – and therefore distinct from human belief (confidence), yet involving it. The Lord continuously births faith in the yielded believer so they can know what He prefers, i.e. The persuasion of His will (1 Jn 5:4).
More scripture here
http://biblehub.com/greek/4102.htm
In Gnostic text the mysteries are only revealed if the adept was willing, because they were considered dangerous in the hands of the profane. Faith could be assimilated with the light that was put inside you in order for you to unlock the mysteries of Jesus teachings. So as I understand it, if you have no faith and do not believe in salvation because of how you have been taught to measure truth, then you will never unlock the mysteries.
Of course faith in everyday life is believing that you can do something, and this brings about actions which either gets or doesn't get the result. Faith is a motivator
As to what I believe, juries still out :)