Grammatically, the sentence is easy to parse and a native English reader would understand how to say it out load.

Agree.

> Clarifying exactly what one wants to say is a central part of writing and editing.

In professional/technical writing, sure? Authors have been known to have different writing styles, and the style may be ambiguous or convoluted to intensify the thoughts or feelings the writer is trying to convey.

PS everyone posting here is a “writer”

> Linda Hale Bucklin made a pact with her husband, Bill, to communicate after death. Here she shares her personal experience and other stories of love and faith in the afterlife.

Bill died after 40 years of marriage.

The rest of the paragraph:

> Bill loved and found solace in nature. Often, we voiced our wonder of the sight of a full moon peeking above the hills of Stinson, rising heavily until it pushed free of the horizon, a perfect circle in the dark sky. On nights with a new moon, we would walk to the end of the beach to find our favorite constellation, the Pleiades. I know Bill carried within him deep currents of spiritual yearning that he found easiest to express through the beauty he saw in all places wild.

Neither of which we believe a machine to be capable of conceiving.

I always use the trick when I write of reading the sentence without the "that"...still makes sense then you don't need "that". Mostly.