If we are to trust...

If we are to trust the fire that cleanses,
The holy pain that meets all saints in turn,
Then through foreign covenanted lenses
Must be seen the flames that heaven's joys earn.
These glasses quite strangely do not make clear,
But e'en obscure still more the cause from view.
'Stead brings before the heart a greater fear,
The God whose word alone preserves the few.
What is this? cries the heart without this gift,
You promised good, yet now abandon me?
But God when seen, our selves entrust to sift,
Treasure costs, clear-eyed men will pay the fee.
And shouldn't Him whose essence makes good good
Define for us what it is? Who else could?