[incomingpain]

Mine is called the Bible. Which is a greek word for "the books" but commonly understood to be "the holy scriptures'. I'm happy to include Quran and Book of Mormon and all gnostic gospels into this mix; it's not important for this discussion.

Pali canon are also a personal favourite. Tao te ching is similarly good.

I havent read the bhagavad gita or the upanishads, but I should do so.

The reality here is that there's a single uncaused God. Even the polytheistic Hindus believe there's only 1 uncaused God(Brahman). But this God is too complex for human understanding. The religions are all bad, very insufficient, explanations of the God with a cultural lens to help in that understanding.

Your importance of your operating manual is to get you to the point that you live at peace with your neighbours and even your enemies. Life is too short to have enemies. Which is then complex about how to avoid ending up with enemies because cultural differences can be the break. Which is the importance of multiple religions.