Theologian in distance comes to centre (6)
I believe the answer is:
middle
'centre' is the definition.
('middle' can be a synonym of 'centre')
'theologian in distance' is the wordplay.
'theologian' becomes 'dd' (Doctor of Divinity degree).
'in' indicates putting letters inside.
'distance' becomes 'mile'.
'dd' placed within 'mile' is 'MIDDLE'.
'comes to' acts as a link.
(Other definitions for middle that I've seen before include "A fine person" , "Intermediate" , "Central" , "Centre point" , "Group of clubs; distance" .)