How come Republicans are the most fervent Christians?

Part of the issue with many religions is that they exists in multiple components. There is

• the religion as the nebulous idea of a culture as adopted by word of mouth generational teaching.

• religion as depicted and codified by a holy script.

• the popculture adoptions of religion through time that become traditionally indistinct.

• the branches of philosophical thought inside the religion changing the window of interpretation and creating schisms

• The economic and power structures involved in maintaining physical sites of worship and a guiding priesthood.

• The political stances the powers inside the religious complex adopt to adapt to specific historical events.

These different factors are generally all at play though there are exceptions like some religions do not have a holy text or sites of worship for instance. Religions are kind of aggregates of time, tradition and thought and distorted by time as well. For instance linguistic and technological drift makes it very hard to appropriately understand a text in it's proper context. Like David and Goliath becomes a very different story when you understand that a sling weilded appropriately is like firing a pistol at short range.

Christianity is kind of a mess in the concept of time. A lot of belief brought into Christianity predated it. Hell for instance predates Christianity (it is not explicitly mentioned in the text but was passed down linguistically) and the conception of it borrowed off of Buddhist, Norse and Grecco/Roman ideas of the underworld. Other things like the Seven Deadly Sins, Lucifer, Monastic living and so on were often inventions of single people who essentially just started fads. Priesthoods have always been tied into concepts of authority through study and internal structures around property. Becoming an abbot was basically just another way to gain the ruling autonomy of nobility for land use. The political structure inside the Church has changed it's relationship with things out of fear as well. The idea of abortion as murder is tracable to the black death when priests worried that a population collapse would cause disaster for society so it changed it's teaching from the concept of "ensoulment" and being very abortion neutral to facilitating a literal witchunt destroying existing systems of female led midwifery to gain reproductive control.

Christianity has at some level always been about power, control and resources... But there are also multiple Christianities. For instance a person who reads the book but rejects the church or the built up dogma of traditions is still a Christian. You can also adopt just the institution or the popculture understanding of Christianity and still be a Christian. Adopting every peice of a religion is itself optional.

The problem being is that understanding the text and history requires a lot of effort, intellectual savvy and time in study. Just like the medieval times people tend to get their understanding from people who did that work for them (or say they did) to supply the missing context. A lot of the time people accept whatever "feels" right and people also tend to be self centric. Feeling superior by category of beliefs we have been handed is something we are all potentially susceptible to.