Sinners supposedly recollecting dead man in prayer (4,3,3)
I believe the answer is:
adam and eve
'sinners supposedly' is the definition.
'recollecting dead man in prayer' is the wordplay.
'recollecting' indicates anagramming the letters.
'in' means one lot of letters goes inside another.
'prayer' becomes 'ave' (I've seen this in other clues).
'dead'+'man'='deadman'
'deadman' is an anagram of 'damande'.
'damande' put inside 'ave' is 'ADAM-AND-EVE'.
(Other definitions for adam and eve that I've seen before include "early marriage?" , "First couple on earth" , "to have faith in cockney" , "pairing from the beginning" , "First two characters" .)