You're talking about favorable advance reviews. You get them by writing a riveting, well-edited book (don't EVER send unedited copies to anyone--really, that's like walking around in your underwear). Then you send it ONLY to people who have told you in advance that they want to read it. And only about a third of those will actually follow through. In your case, I'd contact clergy/leaders from similar faith backgrounds as your own.
Don't send unsolicited copies. That's spam, and you really don't want to build a reputation for doing that.
Other than that, you join the rest of us who scratch and grovel for reviews. They're hard to get, especially with Amazon's tightened regulations. It's a constant problem until you develop a large enough readership that it's not. 'Fraid there's no magic solution here.
ETA: It's okay to send unedited copies to beta readers. That's kinda the whole point of that exercise. I was speaking of a review situation.