Do you feel lucky? Characters who do not rely upon the gods, rely upon fate instead. When each character is created, a d6 is rolled. This determines his or her fate points. No character knows his or her fate points. They just know that they may or may not have some extra luck out there. Any character who has a status of Committed to one or more deities, is protected by higher powers, so does not benefit from Fate.
Similar to Faith Points, Fate Points can be added to die rolls of all kinds to help with attacks, damage, saving throws, skill checks, etc. However, unlike Faith Points, they don't come back on a daily basis, you don't know how many you have, and they can be used singly by anyone that is eligible for them.
To get Fate points back, you have to do something clever. Either think up a cunning idea or do something that is really unusual. If the gods of fate smile upon the action, they will reward you with more fate points. However, you still won't know that has happened until you try to use them and find out you have more.
This encourages good RPing by the not-so-faithful, as they get no points if they just go with the flow.