Reddit reviews Merkabah Rider: High Planes Drifter

This is more Judaism than Christianity but you might be interested in the Merkabah Rider series -- it's a Western that follows a Jewish mystic/gunslinger across the American Southwest. He's in his element when putting down Satanic threats. But then he discovers a more... ancient pantheon.

https://www.amazon.com/Merkabah-Rider-High-Planes-Drifter-ebook/dp/B07F667CNB/