There are other ancient traditions besides Christianity. It might be worth looking at their equivalents or near-equivalents, to see what’s common between them (or particularly insightful in just one).
You probably want to choose traditions that have lived for a long time, not merely existed for a long time. If someone writes a book and it survives 2000 years, that’s some evidence that it’s got valuable insights in it; but if someone writes a book, and then other people work on refining its ideas for 1000 years, and then the results survive another 1000 years, that’s probably better.
There are other ancient traditions besides Christianity. It might be worth looking at their equivalents or near-equivalents, to see what’s common between them (or particularly insightful in just one).
You probably want to choose traditions that have lived for a long time, not merely existed for a long time. If someone writes a book and it survives 2000 years, that’s some evidence that it’s got valuable insights in it; but if someone writes a book, and then other people work on refining its ideas for 1000 years, and then the results survive another 1000 years, that’s probably better.