The theme of the books is reconciliation. Here's Paul on that subject:
1 Corinthians 12:13 For in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free—and all were made to drink of one Spirit. (All scripture quotations from the ESV.)
There is reconciliation even more important than two groups of people becoming reconciled to each other, though:
2 Corinthians 5:20 Therefore, we are ambassadors for Christ, God making his appeal through us. We implore you on behalf of Christ, be reconciled to God.
Getting your priorities right is illustrated.
In the fourth book, a wagon train is about to be attacked by a powerful malice, with its slaves. The Lakewalkers tell the farmers with them to run for cover. But some of them don't want to go.
"The wagons are all we have!" cried Grouse.
"You can't stop to defend things." (The Sharing Knife, Volume Four: Horizon. (New York: Eos, HarperCollins, 2009, p. 209. Grouse is a minor character. Dag is the one who answers him.)
Another man, a smith, is asked if he would rather save his wife or his anvil.
Mark 8:37 For what can a man give in return for his soul?
Luke 12:20 But God said to him, ‘Fool! This night your soul is required of you, and the things you have prepared, whose will they be?’
There is love and fidelity in marriage.
There are a number of happy married couples in the book, including the main characters, Dag and Fawn, but many others, some who have been married for a long time, like Fawn's parents, or Mari and Cattagus, are examples of long-term commitment, and unselfish love for another. (Mari is Dag's aunt, and, until he stopped patrolling, his most recent patrol captain.)
At one point, Dag is approached by a woman, who asks him to be unfaithful to Fawn. He doesn't even consider this, but refuses immediately. Cattagus is disabled, and unable to go on patrol when his wife does, but he and Mari are obviously in a mature spousal love relationship. Dag and Fawn have a number of conversations, throughout the four books. Except when Dag doesn't tell Fawn that he knows she is pregnant right away, there is no hint of dishonesty between them.
The Bible is full of admonitions and examples about this.
There are several examples of moral choices. Some characters make the right choice, some do not.
There is love for the natural world, without worshiping it. Dag shows Fawn his favorite place, a spot on the lake where there are lots of waterlilies. Fawn tells him that she loves milkweed flowers. These plants become part of their wedding cords, objects worn for the duration of a marriage by Lakewalkers.
I believe that stewardship of the natural world is part of God's plan for humans.
There is unselfish service to others. The Lakewalkers, who patrol their own lands, and those of the farmers, for malices, are usually considered to be some sort of freaks, cannibals, and the like by the farmers. The farmers are seldom grateful for this service, and many of them don't even believe it is necessary.
Dag, and other Lakewalkers with healing ability, often give of their time and energy, even putting their lives at immediate risk of being groundlocked, to fix injuries and diseases. Dag and Arkady do this not only for Lakewalkers, but for farmers.
There is a conflict between good and evil.
The evil beings, malices, attack at unexpected times and places, and in unexpected ways. They are able to subvert farmers, even Lakewalkers, to be their slaves, aiding their evil purpose, which is to destroy all that is alive and good. They use their slaves, without regard for their safety, or even their lives. This is much the way that the devil operates, according to the Bible.
As Paul put it:
Ephesians 6:10 Finally, be strong in the Lord and in the strength of his might. 11 Put on the whole armor of God, that you may be able to stand against the schemes of the devil.
And, of course, the most important lesson: Freedom from evil comes only at the cost of a life.
There is no analogy worthy of comparison to the death and resurrection of Christ, the perfect sacrifice for sin, certainly not anything in these books that is so worthy. And there is no hint of a resurrection in them. However, the books do put forth a system wherein the only way to kill a malice is for part of a dying human's ground to be placed into a sharing knife, and that knife be used on the malice.
Thanks for reading. Read the Bible!
The post introducing these books is here. This post is on the theme of the books. This post is on ground, a unique aspect of Bujold's subcreation. A post, on religion in the books, is here.