You and the congregation receiving start of sermon many times over (12)

'many times over' is the definition.
(multiplied by a thousand)

'you and the congregation receiving start of sermon' is the wordplay.
'you' becomes 'thou' (historic second person pronoun).
'the congregation' becomes 'fold' (synonyms).
'receiving' indicates putting letters inside.
'start of' indicates taking the first letters.
The first letter of 'sermon' is 's'.
'thou'+'and'+'fold'='thouandfold'
'thouandfold' going around 's' is 'THOUSANDFOLD'.