Pretty sure this song is about people who have turned away from the Christian Faith for the sake of living the lives they want. "You filled my cup with holy water. I swallowed everything. I joined your ranks of sons and daughters. The army of the slaves" It makes even more sense when you read the following lyrics: "Freedom now remains. One headshot away. Burn you down to make our great escape." Also, the following lyrics: "Worship is worthless. Till we drain our purses. With sanity checked at the door. Reason is useless and what is it for?" are a way of saying that those people don't want to worship and obey God because they have their own feelings to live by.
Pretty sure this song is about people who have turned away from the Christian Faith for the sake of living the lives they want. "You filled my cup with holy water. I swallowed everything. I joined your ranks of sons and daughters. The army of the slaves" It makes even more sense when you read the following lyrics: "Freedom now remains. One headshot away. Burn you down to make our great escape." Also, the following lyrics: "Worship is worthless. Till we drain our purses. With sanity checked at the door. Reason is useless and what is it for?" are a way of saying that those people don't want to worship and obey God because they have their own feelings to live by.
[Edit: To add more details]