Is this sentence grammatically correct?

The sentence is:
On the whole, the poet has effectively used religious imagery to highlight the ritualistic aspects of the photographer’s job, to in turn convey the themes of death, loss and suffering.

Can anyone think of a better way to express the same thing?

Change the bit in bold to "which therefore conveys the themes of death, loss and suffering" and you're good to go

Maybe split it into two separate sentences. Or, if you want a single sentence, use a semi-colon to break it up....

On the whole, the poet has effectively used religious imagery to highlight the ritualistic aspects of the photographer’s job; in turn this effectively conveys the themes of death, loss, and suffering.

*oxford comma thrown in for free*.......................................^