Post about preposterous boozer's story of Christ (7)
I believe the answer is:
parable
'story of christ' is the definition.
'parable' can be an answer for 'story' (parable is a kind of story). I'm not certain of the 'of christ' bit.
'post about preposterous boozer's' is the wordplay.
'post' becomes 'pale' (I've seen this before).
'about' is an insertion indicator.
'preposterous boozer' becomes 'rab' (I can't explain this - if you can you should give a lot more credence to this answer).
'pale' enclosing 'rab' is 'PARABLE'.
Can you help me to learn more?
(Other definitions for parable that I've seen before include "scripture lesson" , "Instructive story" , "Biblical allegory" , "Sower, for one" , "Leap bar poorly for a biblical story" .)