This makes Presbyterian best in prayer (7)
I believe the answer is:
anagram
This could be a double definition.
'this makes presbyterian best' is the first definition.
The definition suggests a singular noun which matches the answer.
'prayer' is the second definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'in' is the link.
Can you help me to learn more?
(Other definitions for anagram that I've seen before include ""Angered" of "enraged", perhaps?" , "Rearrangement of a word's letters to form new word(s)" , "Jumble of letters" , "Nag a ram (anag)" , "pouring the tea?" .)