Leading theologist brought up prophet referring to important organisms (5)
I believe the answer is:
trees
'referring to important organisms' is the definition.
I can't tell whether this defines the answer.
'leading theologist brought up prophet' is the wordplay.
'leading' says to take the initial letters (the leading letter of the word).
'brought up' is a reversal indicator (in a down clue, letters go up).
'prophet' becomes 'seer' (both can mean someone who tells the future).
The initial letter of 'theologist' is 't'.
'seer' back-to-front is 'rees'.
't'+'rees'='TREES'
Can you help me to learn more?
(Other definitions for trees that I've seen before include "Tall, perennial, woody plant" , "Elders perhaps" , "Tall, perennial, woody plants" , "Woods" , "Components of forest" .)