Crucify, we hear, one who gives light (7)

'crucify we hear' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'one who gives light' is the wordplay.
I cannot quite understand how this works, but
'one' could be 'er' (I've seen this in other clues) and 'er' is located in the answer.
'light' could be 'torch' (torch is a kind of light) and 'torch' is present in the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?