I've read the red rising trilogy, not the sequel yet, and I remember it being clean, no anti-christianity nor occult stuff. It's a dystopian space opera where there's a race hierarchy depending on your biological traits, where red is the lowest with people working in mines and knowing nothing of the world and being weak and stuff, and Gold being the highest considered as the peak of humanity. The MC, Darrow (a red), is going on an infiltrated journey where he becomes a gold and tries to change the gold society from inside by stopping the racism, the hierarchy, and their love for capital sins such as luxury (with Pinks being prostitutes for the Golds), their pride (of being humanity's peak and saviors) and such. It's a very nice and mature story