In the Far East, yes, an ancient god! (5)
I believe the answer is:
japan
'in the far east yes an' is the definition.
I can't tell whether this defines the answer.
'ancient god' is the wordplay.
'ancient' becomes 'ja' (I can't explain this - if you can you should give a lot more credence to this answer).
'god' becomes 'Pan' (Pan is a Greek god).
'ja'+'pan'='JAPAN'
Can you help me to learn more?
(Other definitions for japan that I've seen before include "Far Eastern island country" , "'Country of more than 3,000 islands (5)'" , "Country and decorated black lacquerware" , "Glossy black lacquer" , "It's a string of more than 3,000 islands" .)