All this fighting about religion meant that people in Europe spent a lot of time thinking about what they really believed, and by 1630 AD, some people got some new ideas about God. This was the beginning of the Enlightenment. In 1630, Rene Descartes wrote that people should only believe things that had been proven to be true, starting from basic ideas that everyone knew were true. You shouldn't believe things just because your priest told you, or because it was in the Bible.
Descartes set off a whole bunch of other philosophers who tried to do what he said: start from basic ideas and see where that took them. John Locke, for example, argued that we only know things through our senses. Margaret Cavendish wrote that she didn't even believe people had souls.
As scientific thinking got more popular, Christianity got less popular. People started to be angry about all the power and land and money that the Christian bishops and ministers had. In 1750, the Catholic Church owned about six percent of the land in France, and collected its own ten percent income tax (or tithe). By 1763, the French king threw the Jesuits out of France. In 1789, people involved with the French Revolution not only killed the king and the rich men, but also smashed up a lot of churches and monasteries, and took all the Catholic land and money for the new democratic government. The revolutionaries declared that everyone could pray however they wanted - Jews, Muslims, Protestants and Catholics, everyone could have whatever religion they wanted, or none at all.