Highly recommend Time is the Ally of Deceit [1] to get a better understanding of how paganism influenced and was weaved into what we know as modern Christianity. Much of what people identify as Christianity today (Catholicism and Protestantism) is antithetical to what's proposed/commanded by God and Christ in the Bible (and what was observed by early Christians).

[1] https://www.amazon.com/Time-Ally-Deceit-Richard-Rives/dp/098...