I will interrupt passage in church, being artless (5)
I believe the answer is:
naive
'artless' is the definition.
(associated in meaning)
'i will interrupt passage in church' is the wordplay.
'will interrupt' indicates putting letters inside.
'passage in church' becomes 'nave' (I am not sure about this - if you are sure you should believe this answer much more).
'i' placed within 'nave' is 'NAIVE'.
'being' is the link.
Can you help me to learn more?
(Other definitions for naive that I've seen before include "Callow" , "Unsophisticated and gullible" , "Unaffectedly trusting" , "Lacking judgment" , "Lacking sophistication" .)