Child's hero follows papa as a minister (8)
I believe the answer is:
preacher
'a minister' is the definition.
(someone who preaches)
'child's hero follows papa' is the wordplay.
'child's hero' becomes 'Reacher' (Jack Reacher, character in books by Lee Child).
'follows' means one lot of letters go next to another.
'papa' becomes 'P' (phonetic alphabet: alpha, bravo, charlie etc.).
'reacher' after 'p' is 'PREACHER'.
'as' acts as a link.
(Other definitions for preacher that I've seen before include "Religious minister" , "One spreads the message" , "Someone spreading a gospel" , "Minister, clergyman" , "Gospeller" .)