Tender Christian missionary recruiting in force (7)

I believe the answer is:

painful

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'tender' is the definition.
(similar in meaning)

'christian missionary recruiting in force' is the wordplay.
'christian missionary' becomes 'paul' (St Paul. I am not sure about the 'christian' bit.).
'recruiting' is an insertion indicator (inserted letters are recruited into the word).
'force' becomes 'F' (symbol used in Physics e.g. f=ma).
'in'+'f'='inf'
'paul' placed around 'inf' is 'PAINFUL'.

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(Other definitions for painful that I've seen before include "Tender" , "Inflamed" , "Causing physical discomfort" , "Sore" , "Agonising" .)

I've seen this clue in The Times.

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