One has faith one will go far (7)
I believe the answer is:
pilgrim
'one' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for pilgrim that I've seen before include "Person who journeys for religious reasons" , "Traveller to a holy place" , "... emigrants to Massachusetts" , "One progressive type" , "made progress, as booked" .)