Gabriel had a main role in this part of scripture (7)
I believe the answer is:
genesis
This clue might be a double definition.
'gabriel had a main role in this' is the first definition.
The definition suggests a singular noun which matches the answer.
'part of scripture' is the second definition.
(I know that Genesis is part of Old Testament)
Can you help me to learn more?
(Other definitions for genesis that I've seen before include "Beginning the holy book" , "First book of the Old Testament" , "Band; book" , "First book of the Bible" , "rock group" .)