I don't know if there's one available - most of the modern Bible versions are copyrighted. And then there's the question of which version you want.

The easiest way might be to use biblegateway.com https://www.biblegateway.com/usage/

You can also use $modx->query('YOUR SQL HERE') which returns an array of the results, which may be easier to incorporate into your code while using the existing connection to MySQL.

When developing snippets it's typically better to use a single return instead of echo-ing data to the screen. You do have a lot of echo-ing going on, so it may be easier to leave it as-is for now, unless you're going all-in for refactoring If you are, also consider using chunks for the html parts with placeholders as to split markup and logic.