Lose one's nerve, putting deity in charge (5)
I believe the answer is:
panic
'lose one's nerve' is the definition.
(I've seen this before)
'deity in charge' is the wordplay.
'deity' becomes 'pan' (Pan is an example).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'pan'+'ic'='PANIC'
'putting' acts as a link.
(Other definitions for panic that I've seen before include "Frantic fright" , "Alarm - terror" , "Greek god" , "Go to pieces" , "much unease" .)