That is a good question. The source of your confusion is the construction TO BE + INFINITIVE. This construction is not used a lot, but it is used, so it is good to become acquainted with its numerous meanings. Since it can mean so many different things, it is impossible, without more context, to say exactly what your sentence means. "We are to search" can mean any of the following: "It is intended that we search" "It is our duty to search" "We are the ones who will search" "We will search" "Let us search!" (imperative) "It is our plan to search"

The sentence is grammatically correct. We are to search for wisdom as we would a hidden treasure. = We are to search for wisdom as we would (search for) a hidden treasure. So apparently it is a sentence with a ellipsis.

"We are to X..." = We have been given a command to do X. We have been ordered to do X. We are expected to do X. We have a duty to do X. "...as we would Y" In the same way as we would do Y. "We are to X as we would Y" = we should do X in the same way we would do Y.

Don't read too much into the grammatical choices of the passage. This is just one translation of one part of an ancient text that was originally written in Hebrew (I can't be more specific without triggering the automated content filters.) Most other interpretations of this particular verse in English sound even more convoluted.

I’ll keep in mind “ poetic license” That sounds interesting. Thank you:)