The most common and most likely answer to this crossword clue is the 10 letter word ISRAELITES
I've seen this crossword clue in Financial Times
I
S
R
A
E
L
I
T
E
S
More clues leading to the result ISRAELITES
- Old people realise it’s silly
- Returning group I linked with humorist – South Island believers?
- Realise it’s about Biblical Hebrews
- Isaiah appointed one king from the east for the Jews
- Jacob’s descendants find the non-performing personalities starting off by mistake
- Is artist chosen son from chosen people?
Buddy explains!
The straight part
We know that "believers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case believers = israelites.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.