Penitent opposed to Middle-Eastern liturgy (8)
I believe the answer is:
contrite
'penitent' is the definition.
('contrite' can be similar in meaning to 'penitent')
'opposed to middle-eastern liturgy' is the wordplay.
'opposed' becomes 'con' (I've seen this before).
'to middle' says to take the centre.
'liturgy' becomes 'rite' (I've seen this before).
The middle of 'eastern' is 't'.
'con'+'t'+'rite'='CONTRITE'
(Other definitions for contrite that I've seen before include "Full of remorse" , "Penitent, feeling guilty" , "Repentant and chastened" , "Feeling remorse" , "Repentant, remorseful" .)