Artless one maybe found in part of church (5)
I believe the answer is:
naive
'artless' is the definition.
(associated in meaning)
'one maybe found in part of church' is the wordplay.
'one maybe found' becomes 'i' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' is an insertion indicator.
'part of church' becomes 'nave' (area of a church building).
'i' inserted within 'nave' is 'NAIVE'.
Can you help me to learn more?
(Other definitions for naive that I've seen before include "Jejune" , "Unaffected or guileless" , "Simple and guileless" , "Innocent or not worldly enough" , "Showing lack of experience or sophistication" .)