Genre is not the main question
Science fiction can explore courage, sacrifice, human pride, creation, justice and hope. Those are not foreign to Scripture. It can also carry ideas or images that pull a reader towards fear, sexual immorality, cruelty, despair or fascination with practices God forbids. So the useful question is not simply, “Is this science fiction?” It is, “What is this story doing in me?”
Paul told the Corinthian church that not everything lawful is helpful or strengthening. He was teaching Christians to use their freedom with love and wisdom, rather than treating freedom as a reason to consume anything without reflection (1 Corinthians 10:23).
All things are lawful for me, but all things are not expedient: all things are lawful for me, but all things edify not.
Pay attention to the story's direction
A fictional world may include evil without asking you to admire it. Scripture itself honestly shows murder, betrayal, idolatry and oppression. The difference is that it does not call darkness good. When considering a book or film, notice whether wrongdoing is exposed or made attractive, whether people are treated as bearing dignity, and whether the story leaves you feeding thoughts you know are unhealthy.
Paul gives a positive direction for the mind: dwell on what is true, honourable, just, pure, lovely and worthy of praise (Philippians 4:8). That does not require every story to be cheerful or simple. It does mean entertainment should not steadily train your imagination away from those things.
Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.
Be careful with spiritual themes
Some science fiction uses invented powers, alien religions, magic or occult language as parts of a fictional setting. Christians reach different conclusions about particular stories. An imaginary element is not automatically the same as practising the occult. Still, God clearly warns his people not to seek divination, sorcery or communication with the dead (Deuteronomy 18:10-12).
If a story stirs a desire to explore forbidden spiritual practices, normalises them, or troubles your conscience, step away. You do not need to prove maturity by watching what disturbs your peace. Test what you are taking in, hold on to what is good, and turn from what is evil (1 Thessalonians 5:21-22).
Let love and conscience guide you
One Christian may be able to enjoy a space adventure with gratitude, while another finds its violence, cynicism or spiritual imagery unhelpful. Neither should casually judge the other. Romans 14 teaches that acting against your conscience is not faith, so honesty before God matters here (Romans 14:23).
A simple practice can help. Before and after watching or reading, ask: Can I thank God for this? Is it shaping me towards love, courage and truth, or towards temptation and numbness? Is it taking a place that belongs to prayer, rest, relationships or Scripture? Then choose freely, but choose deliberately. Whatever you do, Paul says, do it for God's glory (1 Corinthians 10:31).
Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God.