I'm 17. I am a Christian. This review is aimed towards the Christian teenagers out there.
This show contains some very harmful themes in it.
1. It contains some actual occultic references and themes. Yuji goes to an actual occult club at his school where he finds something called a cursed object. It was this dead guy's finger (the dead guy was named Sukuna). He ends up eating it which was cannibalism. What happens next was even darker because Sukuna's soul was still inside the finger. His soul tried taking over Yuji's body and essentially was able to possess him and use him to kill a ton of people in the second season. He took Yuji over multiple times in both the first and second season. I took a step back and realized that this show was portraying a 15-year-old child being literally POSSESSED and USED by a demon. That's a very dark and negative concept to entertain.
2. The protagonists are sorcerers who use Cursed Energy (negative spiritual energy) to fight cursed spirits, so they are essentially using demonic energy. The Bible condemns sorcery and the usage of demonic powers because they are extremely DANGEROUS spiritually, and even mentally, emotionally, and physically.
3. Characters like Megumi can summon and use Cursed Spirits/demons to fight. A character named Nobara also has a Cursed Technique that heavily resembles Voodoo doll stuff. That's all SUPER demonic. Like, this is not something we should entertain ourselves with.
I just want to say that it's not worth it. You're not cooler or better because of what you watch. You're not losing anything by skipping shows like this. Also know that God isn't mad at you for learning and making mistakes even if you do watch it. However, this show does contain multiple spiritually dangerous themes, and if you love yourself, find something healthier. You're not missing anything, it will be ok.