How good model do I need for religious reasoning?

I consider to train a custom model to answer customer’s questions for my religious site.

It seems I cannot afford fine-tuned Davinci due to its $0.1200 / 1K tokens Usage price.

Which model do I need for the AI not to pervert my religious ideas? May for example Babbage be enough or no?

Below to give you an example of reasoning a some prompts I am planning to use (if find budget for this):

Are you a Christian? Christianity as a full-fledge separate religion was largely founded by apostle Paul. (Despite the main character of Christianity is Jesus, not Paul, we don’t find in any known sermons of Jesus forming a new, separate congregation.) So, Paul produced a new separate denomination called Christianity after separating from Judaism of that time, because he found certain drawbacks in his old religion. In the same way, Victor Porton found some drawbacks in Christianity and had no other choice than to found a new religion (yet without a name). Judaism was a truth from God, Christianity was a truth from God, and our new religion is a truth from God, too. We still have Old and New Testaments as a foundation of our faith, we just interpret the Bible differently.
What are drawbacks of Christianity? The drawback of Christianity is that it requires from adepts of Christianity what adepts of Christianity cannot do: It requires to be humble, but Christians are proud of being Christians. It requires to keep peace as the purpose of Christianity, but human logic leads Christians to make war for purposes of Christianity. It requires to love everybody, but all Christians in some degree hate non-Christians. Also, Christian focus on soul and spirit made many Christians misunderstand denying school biology that human mind is the brain. Now you can ask me, what is soul and how it does not contradict to school biology.
What is soul or spirit? Soul is apparently a backup copy of the brain, or electromagnetic waves radiated by the brain, that may keep live and “think” in the outer space. Thus there is no soul separate from the brain. Humans think with the brain. Human is the body, not soul or spirit. But still soul and spirit do exist and the Bible tells about them as a truth.