A theologian was first to get confused (6)
I believe the answer is:
addled
'confused' is the definition.
(addling is a kind of confusing)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for addled that I've seen before include "Confused like infertile egg" , "Mentally confused, muddled" , "Confused like rotten egg" , "Perplexed -- rotten" , "Foolish or confused like bad egg" .)