Timothy Zahn is one of my favorite writers and has been very influential in my own writing. Like me, Zahn writes a lot of space opera, and he's most famous for his Thrawn series of Star Wars novels. But he's been writing a long time and has some great other stuff as well. His Quadrail series (Night Train to Rigel, Odd Girl Out, etc), in particular, is a great read.
Recently, I heard about another of his books, Deadman Switch, which features spiritual themes. Since I use a lot of spiritual themes in my specfic, I wanted to check it out. It was published in 1988 and is out of print, but I tracked down a copy on Amazon and read it last week. What a fantastic read. I highly recommend it.
A bit more of a mystery than a space opera, the premise of the book is that the Patri, a coalition of planets, has found a rich source of minerals in the rings and moons around the planet Solitaire. There's only one catch, the system is surrounded by a mysterious cloud which prevents ships from entering. The only way in is using the Deadman Switch -- carrying a zombi along who is killed and then flies the ship through the cloud. Death Row inmates have become the zombis of choice, and when his boss buys a large conglomerate on Solitaire to get a license to travel there, Gilead Raca Benedar is sent with the boss' son to check out the new property and tend to details.
The problem is that Gilead belongs to a Christian order called "the Watchers,"
who have unique powers of perception allowing them to read minds. His integrity and values raise objections with the Deadman Switch idea, but then he discovers that one of the zombis on their ship (they carry two -- one to go in, one to get out) is a fellow Watcher, and Gilead is convinced she's innocent. When he sets out to prove it, drama ensues.
Eventually, Gilead takes drastic steps to protect her and escapes with her to the nearby planet Spall, hoping to find Smugglers raiding the system to use as zombis instead. In the process, they discover a new form of intelligent life previously undiscovered and end up launching a huge investigation and scientific inquiry which ropes in both watchers, Gilead's boss, local officials, and a local religious sect. When it is discovered that a large fleet is on its way to attack the system, Gilead and the others scramble to find a way to deal with the situation.
If I tell you more, you would know too much, so I'll leave it there, but suffice it to say the ending has plenty of surprises and the book is a great read. I read 50 pages a day until the last day when I read over 100 because I just had to know what happens. I would have read more other days too but have too much going on. It's a pageturner, in other words, and filled with Zahn's trademark solid science, interesting and complex characters and complicated, unfolding plotting. Truly a great read, and if you can track it down, I highly recommend doing so.
The spiritual themes are used similarly to the way I use them in my work: Christian influenced characters without being preachy, so I think even those scifi fans who are agnostic or not fans of religion would enjoy it.
I put a link to Zahn's site on my website. I highly recommend checking out his books. You won't regret it.
For what it's worth...