Search in gospel to protect love -- what's that ? (8,4)
I believe the answer is:
question mark
'that ?' is the definition.
(I've seen this before)
'search in gospel to protect love' is the wordplay.
'search' becomes 'quest' (I've seen this before**).
'gospel' becomes 'mark' (Gospel of Mark).
'to protect' is an insertion indicator.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'in'+'mark'='inmark'
'inmark' going around 'o' is 'ionmark'.
'quest'+'ionmark'='QUESTION-MARK'
'what's' is the link.
(Other definitions for question mark that I've seen before include "Expression of uncertainty" , "Not believe the gospel" , "Query" , "What ends this" .)