The most common and most likely answer to this crossword clue is the 7 letter word RETABLE
I've seen this crossword clue in The Guardian
R
E
T
A
B
L
E
Buddy explains!

The straight part
We know that "setting for religious objects" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case setting for religious objects = retable.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does RETABLE mean?
RETABLE noun- A table or shelf behind an altar, on which are placed images or holy objects.
- To table again.