Artist is corrupt and about to steal lead from churches (8)
I believe the answer is:
sculptor
'artist' is the definition.
(I know that sculptor is a type of artist)
'corrupt and about to steal lead from churches' is the wordplay.
'corrupt' becomes 'rot'.
'and' becomes 'plus'.
'about' says the letters should be written in reverse.
'to steal' is an insertion indicator.
'lead from' indicates taking the first letters (the letter that leads the word).
The first letter of 'churches' is 'c'.
'rot'+'plus'='rotplus'
'rotplus' backwards is 'sulptor'.
'sulptor' going around 'c' is 'SCULPTOR'.
'is' acts as a link.
(Other definitions for sculptor that I've seen before include "Artist in stone, bronze etc" , "Artist - pro cults (anag)" , "Artist carving stone or wood" , "A carver of statuary" , "Henry Moore, for one" .)