Study of the Divine Comedy finally follows the old official account (8)
I believe the answer is:
theology
'study of the divine' is the definition.
(I've seen this before)
'comedy finally follows the old official account' is the wordplay.
'finally' suggests the final letters.
'follows' is a charade indicator (letters next to each other).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'official account' becomes 'log'.
The final letter of 'comedy' is 'y'.
'the'+'o'+'log'='theolog'
'y' after 'theolog' is 'THEOLOGY'.
(Other definitions for theology that I've seen before include "Study of God, etc" , "Study of religious beliefs" , "Bible study" , "Systematic study of religion" , "Religious studies" .)