Ask Lemmy

https://en.wikipedia.org/wiki/Puritans

https://en.wikipedia.org/wiki/Calvinism

You probably don't want to read all that so here's a what I think is the important take away as far as your question is concerned. American Christians have always been a bit different from the mainstream religion elsewhere. The largest Christian group to come to America in the early colonial period were called the Puritans. They believed that the English Reformation did not go far enough. They were staunchly anti-Catholic and were very upset that the Church of England had adopted so much theology and tradition from the Catholic Church.

The Puritans believed that the Bible is the complete revelation of God rejecting the papacy, the concept of continuing revelations, and the related concept of the Divine Right of Kings. They believed that individuals forged their own covenant with God and that their belief and acceptance was all that in required for their salvation. That sin is so pervasive in our corrupt world that it was unavoidable, no person can be "good" or worthy of salvation and so salvation is only available through God's mercy. They believed that it was their role as Christians to fight against the corruption of the world by spreading their theology and enforcing their concepts of sin and redemption on each other and on the greater community. The narrative is that they fled Europe to avoid religious persecution. The persecution that they faced was that they were not allowed to make laws banning things like alcohol or "revealing" clothing that they considered sinful or forcing people to go to their churches.

They adopted most of there theology from a reformist movement called Calvinism that sought to expand the Protestant Reformation further stripping away the power of the clergy and empower believers to enforce theology. Calvinists adopted an extremely socially conservative interpretation of the Bible and supported strict adherence to their moral ideology and severe punishment for violations of their concept of morality.

The modern Christian movements that trace themselves back to that foundation are still the largest Christian groups in the US. In the 1960's the Republican party began the "Southern Strategy" which was shift of political focus to conservative social issues and attacking secular institutions. Republicans used this strategy to unite the philosophical descendants of the Puritans under a political ideology that is strongly focused on conservative social issues and on pushing their concepts of religion and morality into all aspects of society enforcing adherence through government.

https://en.wikipedia.org/wiki/Prosperity_theology

Prosperity theology is a newer theological concept that was popularized by Oral Roberts, has been embraced by the Republican party, and allowed the rise of the megachurch and celebrity preachers. Basically Prosperity theology gives an answer to the question of how you know that that someone is "living right" and a solution to the problem of evil. You know that someone is "living right" because God rewards their righteousness with material wealth. Evil exists as a punishment for the corruption of the secular world. Bad things primarily happens to the unholy but evil spills over to the righteous because secular corruption is so pervasive as to make sin unavoidable in our fallen world. Poverty is the primary form of punishment God visits upon the unholy.

You say you are from a predominantly Christian country so I assume that you are sufficiently familiar with the Gospels to recognize that this is a significant departure from the teachings of Jesus as presented in the Bible. I dare say that the departure is significant enough to be called an outright rejection of the teachings of the purported source of their morality and salvation.