PHP search function

Hello all! First, let me say this is not the WP search i am asking about. Second, i would like to be able to search for words in an online Bible that i have. If you goto https://www.mytimewithgod.net and click on “Bible”, you will see that all the books of the Bible are there and at the top of the page is where i would like a “search function” Can someone point me in the right direction as “how to get a search for this online Bible”? I have a “half-written” search but it is not working right. Any help is appreciated.