They could be the best in prayers! (13)
I believe the answer is:
presbyterians
'they' is the definition.
Both the answer and definition are plural nouns.
Perhaps there's a link between them I don't understand?
'could be the best in prayers' is the wordplay.
'could be' indicates anagramming the letters.
'best'+'in'+'prayers'='bestinprayers'
'bestinprayers' anagrammed gives 'PRESBYTERIANS'.
Can you help me to learn more?
(Other definitions for presbyterians that I've seen before include "Church people" , "Protestant church members" , "Followers of a branch of Calvinism - Britney Spears (anag)" , "Calvinists" , "Followers of John Knox" .)