No sane company will add real‑world religions to The Sims. The only time the series ever touched religion was in Sims Medieval, and those were completely fictional faiths worshiping the Watcher (the player). If EA adds Christianity, they’re going to have to add every other religion as well, and that’s a guaranteed controversy storm.
And as soon as you add real religious items, those items can be instantly abused. Sims players can burn objects, curse them, destroy them, or use them in chaos builds. With Spellcasters, someone will immediately make a video of their Sim setting a Bible or the Quran on fire with Inferniate. EA is not going to risk that.
Fictional religions are the only safe option.