Old record those people keep for study of religion (8)
I believe the answer is:
theology
'study of religion' is the definition.
(I've seen this before)
'old record those people keep' is the wordplay.
I cannot quite understand how this works, but
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is present in the answer.
'record' could be 'log' (logging is a kind of recording) and 'log' is found in the answer.
'those people' could be 'they' (I've seen this before) and 'they' is located in the remaining letters.
No letters remain.
This explanation may well be incorrect...
'for' acts as a link.
Can you help me to learn more?
(Other definitions for theology that I've seen before include "Study of religious beliefs" , "Religious studies" , "Systematic study of religion" , "Study of the divine" , "Study of God, etc" .)