Aliens. Lasers. Warp drives. Spaceships. Battles with lots of people named "commander" or "ensign."
These are just a few of the things that probably come to your mind when someone mentions "science fiction." And you wouldn't be wrong—in most examples of the genre, those things exist in spades. Even if a show doesn't revolve around massive space battles, there are at least a few futuristic weapons to be seen, robots to be used (or fought), and planets to be explored.
But science fiction can also be a conduit to ask serious questions about faith, religion, purpose, destiny, and what, exactly, it means to be human. They're questions not usually possible to ask in other genres—at least, not as easily. The setting, scope, and plot of most science fiction makes it possible to explore themes that have puzzled humans since the beginning of time—including themes that crop up, again and again, in the Bible.
The Deeper Side of Sci-Fi
Perhaps the most obvious way science fiction portrays spirituality is in the examination of the human spirit under difficult, even alien (pun fully intended) situations. Like no other genre, science fiction can ably and quickly ask deep, probing questions, such as, "What does decency look like in the midst of insurmountable odds and threats to human existence?"
Even the silliest, most vapid science fiction seems to hinge on how loving humanity can be in the face of seemingly insurmountable odds. The transformers films are generally not very good, but they still rely on the fact that the heroes sacrifice for one another, help one another, and act out a near-biblical love for each other. Independence day is practically the definition of "popcorn flick," but it features a father willing to die out of love for his children, along with a President willing to die for people all over the world. And knowing wouldn't ever win any awards for its ludicrous story, but it's still about sacrificial love. In fact, almost every disaster film (be it via attack by aliens, meteor, or a mish-mash of natural causes) forces its characters into choices about what kinds of people they will be. In almost all of them, the honorable characters choose to sacrifice and protect their loved ones out of selflessness, a deeply 1 Corinthians 13-type love.
But the best science fiction asks even deeper questions. Consider a show like lost (or, to a lesser extent, its spiritual successor fringe). Over its six sometimes infuriating seasons, it managed to cover time travel, dualistic mythology, and the afterlife. But at its core was a question of belief: Was it better to rely on faith or reason? The two sides were represented by John Locke, the ultimate faithful one, and Jack Shepard, the ultimate man of rationality. In the end, neither man is completely proven right [spoilers ahead]. Locke's passionate faith takes him past empathy and compassion and ultimately leads to his murder, and Shepard's rationality costs him everything until he truly believes.
Both of these characters represent extremes that Jesus calls Christians away from in the Gospels. Jesus obviously shows deep faith—so much faith that he willingly goes to his death even though he doesn't want to. But he also perfectly lived out a life that married deep compassion (as when he healed the blind man in John 9) with deep conviction (as when he rebuked Peter for his lack of faith in Mark 8). Shows like lost encourage a stance of a compassionate faith that goes beyond raw reason, but also doesn't succumb to a lack of empathy for broken people. It's a show that strongly suggests there's something beyond what we can understand through rationalism.