I agree with this 100%. But...
Here I have a problem. "How religion was practiced prior to the 19th century," is a very, very expansive category. There is a poem known as "The Sister's Message" - it is an ancient Mesopotamian tract - maybe 4000 years old? Anyway:
As I was strolling, as I was strolling
as I was strolling by the house
my dear Inanna saw me
O, my brother, what did she tell me? What did she tell me?
What more did she say to me?
O, my brother of love; allure
The sweetest of sweet things.
I think the poet had "a personal relationship with" Inanna. The poem goes on - it is sort-of written from a woman's perspective, although a man undoubtedly wrote it - and is confiding in the goddess; maybe asking her for romantic advice; there is also a heavy erotic subtext. There are other tracts, thousands of years old, which bespeak other - very diverse and very complex - understandings of the notion of "deity." I think we fundamentally underestimate and misrepresent people in ancient cultures when we portray their personal religious experience and understanding - and how they construe divinity - as somehow different, inferior, less evolved, less informed than our own.