Grammar, sentence structure

As long, brethren, as the moon and sun have not arisen in the world, just as long is there no shining forth a great light of great radiance. just as long is there no shining forth a great light of great radiance.

=

I would like to rewrite the main clause thus:

"It is just as long (as the non-arising of the moon and sun in the world) that a great light of great radiane does not shine forth."

Please point out the mistakes in my rewriting.

Thank you in advance!