The most common and most likely answer to this crossword clue is the 5 letter word AGAPE
I've seen this crossword clue in Financial Times
A
G
A
P
E
More clues leading to the result AGAPE
- Looking astonished as assistant’s back in time (5
- Wide open love Christian shows
- Stare in wonder after a religious feast
- Love yawning
- Kind of love that’s very open, like 8 and 15 exemplifying 3 7
- Appearing shocked by deficit in part of hospital
- Love break in hospital department
- Wide open space in hospital department
- Christian’s love showing disbelief
- Having mouth wide open in Christian feast
Buddy explains!

The straight part
We know that "religious feast" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case religious feast = agape.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 AGAPE mean?
AGAPE adjective- In a state of astonishment, wonder, expectation, or eager attention; as with mouth hanging open.
- Wide open.
- In a state of astonishment, wonder, expectation, or eager attention.
- Open wide.
- The love of God for mankind, or the benevolent love of Christians for others.
- Spiritual, altruistic, beneficial love which wills good for others.
- A love feast, especially one held in the early Christian Church in connection with the Eucharist.